| Age | Commit message (Collapse) | Author |
|---|
|
Patch series "Control over userfaultfd kernel-fault handling", v6.
This patch series is split from [1]. The other series enables SELinux
support for userfaultfd file descriptors so that its creation and movement
can be controlled.
It has been demonstrated on various occasions that suspending kernel code
execution for an arbitrary amount of time at any access to userspace
memory (copy_from_user()/copy_to_user()/...) can be exploited to change
the intended behavior of the kernel. For instance, handling page faults
in kernel-mode using userfaultfd has been exploited in [2, 3]. Likewise,
FUSE, which is similar to userfaultfd in this respect, has been exploited
in [4, 5] for similar outcome.
This small patch series adds a new flag to userfaultfd(2) that allows
callers to give up the ability to handle kernel-mode faults with the
resulting UFFD file object. It then adds a 'user-mode only' option to the
unprivileged_userfaultfd sysctl knob to require unprivileged callers to
use this new flag.
The purpose of this new interface is to decrease the chance of an
unprivileged userfaultfd user taking advantage of userfaultfd to enhance
security vulnerabilities by lengthening the race window in kernel code.
[1] https://lore.kernel.org/lkml/20200211225547.235083-1-dancol@google.com/
[2] https://duasynt.com/blog/linux-kernel-heap-spray
[3] https://duasynt.com/blog/cve-2016-6187-heap-off-by-one-exploit
[4] https://googleprojectzero.blogspot.com/2016/06/exploiting-recursion-in-linux-kernel_20.html
[5] https://bugs.chromium.org/p/project-zero/issues/detail?id=808
This patch (of 2):
userfaultfd handles page faults from both user and kernel code. Add a new
UFFD_USER_MODE_ONLY flag for userfaultfd(2) that makes the resulting
userfaultfd object refuse to handle faults from kernel mode, treating
these faults as if SIGBUS were always raised, causing the kernel code to
fail with EFAULT.
A future patch adds a knob allowing administrators to give some processes
the ability to create userfaultfd file objects only if they pass
UFFD_USER_MODE_ONLY, reducing the likelihood that these processes will
exploit userfaultfd's ability to delay kernel page faults to open timing
windows for future exploits.
Link: https://lkml.kernel.org/r/20201120030411.2690816-1-lokeshgidra@google.com
Link: https://lkml.kernel.org/r/20201120030411.2690816-2-lokeshgidra@google.com
Signed-off-by: Daniel Colascione <dancol@google.com>
Signed-off-by: Lokesh Gidra <lokeshgidra@google.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: <calin@google.com>
Cc: Daniel Colascione <dancol@dancol.org>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Joel Fernandes (Google)" <joel@joelfernandes.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nitin Gupta <nigupta@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Shaohua Li <shli@fb.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
ARM is the only architecture that defines CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
which in turn enables memmap_valid_within() function that is intended to
verify existence of struct page associated with a pfn when there are holes
in the memory map.
However, the ARCH_HAS_HOLES_MEMORYMODEL also enables HAVE_ARCH_PFN_VALID
and arch-specific pfn_valid() implementation that also deals with the holes
in the memory map.
The only two users of memmap_valid_within() call this function after
a call to pfn_valid() so the memmap_valid_within() check becomes redundant.
Remove CONFIG_ARCH_HAS_HOLES_MEMORYMODEL and memmap_valid_within() and rely
entirely on ARM's implementation of pfn_valid() that is now enabled
unconditionally.
Link: https://lkml.kernel.org/r/20201101170454.9567-9-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Meelis Roos <mroos@linux.ee>
Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
As kernel expect to see only one of such mappings, any further operations
on the VMA-copy may be unexpected by the kernel. Maybe it's being on the
safe side, but there doesn't seem to be any expected use-case for this, so
restrict it now.
Link: https://lkml.kernel.org/r/20201013013416.390574-4-dima@arista.com
Fixes: commit e346b3813067 ("mm/mremap: add MREMAP_DONTUNMAP to mremap()")
Signed-off-by: Dmitry Safonov <dima@arista.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
For many workloads, pagetable consumption is significant and it makes
sense to expose it in the memory.stat for the memory cgroups. However at
the moment, the pagetables are accounted per-zone. Converting them to
per-node and using the right interface will correctly account for the
memory cgroups as well.
[akpm@linux-foundation.org: export __mod_lruvec_page_state to modules for arch/mips/kvm/]
Link: https://lkml.kernel.org/r/20201130212541.2781790-3-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Running stress-ng on ocfs2 completely fills the kernel log with 'max
lookup times reached, filesystem may have nested directories.'
Let's ratelimit this message as done with others in the code.
Test-case:
# mkfs.ocfs2 --mount local $DEV
# mount $DEV $MNT
# cd $MNT
# dmesg -C
# stress-ng --dirdeep 1 --dirdeep-ops 1000
# dmesg | grep -c 'max lookup times reached'
Before:
# dmesg -C
# stress-ng --dirdeep 1 --dirdeep-ops 1000
...
stress-ng: info: [11116] successful run completed in 3.03s
# dmesg | grep -c 'max lookup times reached'
967
After:
# dmesg -C
# stress-ng --dirdeep 1 --dirdeep-ops 1000
...
stress-ng: info: [739] successful run completed in 0.96s
# dmesg | grep -c 'max lookup times reached'
10
# dmesg
[ 259.086086] ocfs2_check_if_ancestor: 1990 callbacks suppressed
[ 259.086092] (stress-ng-dirde,740,1):ocfs2_check_if_ancestor:1091 max lookup times reached, filesystem may have nested directories, src inode: 18007, dest inode: 17940.
...
Link: https://lkml.kernel.org/r/20201001224417.478263-1-mfo@canonical.com
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
A break is not needed if it is preceded by a goto
Link: https://lkml.kernel.org/r/20201019175216.2329-1-trix@redhat.com
Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This variable isn't used anymore, remove it to skip W=1 warning:
fs/ntfs/inode.c:2350:6: warning: variable `attr_len' set but not used [-Wunused-but-set-variable]
Link: https://lkml.kernel.org/r/4194376f-898b-b602-81c3-210567712092@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Anton Altaparmakov <anton@tuxera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
We actually don't use these varibles, so remove them to avoid gcc warning:
fs/ntfs/file.c:326:14: warning: variable `base_ni' set but not used [-Wunused-but-set-variable]
fs/ntfs/logfile.c:481:21: warning: variable `log_page_mask' set but not used [-Wunused-but-set-variable]
Link: https://lkml.kernel.org/r/1604821092-54631-1-git-send-email-alex.shi@linux.alibaba.com
Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Acked-by: Anton Altaparmakov <anton@tuxera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Pull io_uring fixes from Jens Axboe:
"Two fixes in here, fixing issues introduced in this merge window"
* tag 'io_uring-5.10-2020-12-11' of git://git.kernel.dk/linux-block:
io_uring: fix file leak on error path of io ctx creation
io_uring: fix mis-seting personality's creds
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs
Pull zonefs fix from Damien Le Moal:
"A single patch in this pull request to fix a BIO and page reference
leak when writing sequential zone files"
* tag 'zonefs-5.10-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs:
zonefs: fix page reference and BIO leak
|
|
When we try to visit the pagemap of a tagged userspace pointer, we find
that the start_vaddr is not correct because of the tag.
To fix it, we should untag the userspace pointers in pagemap_read().
I tested with 5.10-rc4 and the issue remains.
Explanation from Catalin in [1]:
"Arguably, that's a user-space bug since tagged file offsets were never
supported. In this case it's not even a tag at bit 56 as per the arm64
tagged address ABI but rather down to bit 47. You could say that the
problem is caused by the C library (malloc()) or whoever created the
tagged vaddr and passed it to this function. It's not a kernel
regression as we've never supported it.
Now, pagemap is a special case where the offset is usually not
generated as a classic file offset but rather derived by shifting a
user virtual address. I guess we can make a concession for pagemap
(only) and allow such offset with the tag at bit (56 - PAGE_SHIFT + 3)"
My test code is based on [2]:
A userspace pointer which has been tagged by 0xb4: 0xb400007662f541c8
userspace program:
uint64 OsLayer::VirtualToPhysical(void *vaddr) {
uint64 frame, paddr, pfnmask, pagemask;
int pagesize = sysconf(_SC_PAGESIZE);
off64_t off = ((uintptr_t)vaddr) / pagesize * 8; // off = 0xb400007662f541c8 / pagesize * 8 = 0x5a00003b317aa0
int fd = open(kPagemapPath, O_RDONLY);
...
if (lseek64(fd, off, SEEK_SET) != off || read(fd, &frame, 8) != 8) {
int err = errno;
string errtxt = ErrorString(err);
if (fd >= 0)
close(fd);
return 0;
}
...
}
kernel fs/proc/task_mmu.c:
static ssize_t pagemap_read(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
...
src = *ppos;
svpfn = src / PM_ENTRY_BYTES; // svpfn == 0xb400007662f54
start_vaddr = svpfn << PAGE_SHIFT; // start_vaddr == 0xb400007662f54000
end_vaddr = mm->task_size;
/* watch out for wraparound */
// svpfn == 0xb400007662f54
// (mm->task_size >> PAGE) == 0x8000000
if (svpfn > mm->task_size >> PAGE_SHIFT) // the condition is true because of the tag 0xb4
start_vaddr = end_vaddr;
ret = 0;
while (count && (start_vaddr < end_vaddr)) { // we cannot visit correct entry because start_vaddr is set to end_vaddr
int len;
unsigned long end;
...
}
...
}
[1] https://lore.kernel.org/patchwork/patch/1343258/
[2] https://github.com/stressapptest/stressapptest/blob/master/src/os.cc#L158
Link: https://lkml.kernel.org/r/20201204024347.8295-1-miles.chen@mediatek.com
Signed-off-by: Miles Chen <miles.chen@mediatek.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Song Bao Hua (Barry Song) <song.bao.hua@hisilicon.com>
Cc: <stable@vger.kernel.org> [5.4-]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Pull NFS client fixes from Anna Schumaker:
"Here are a handful more bugfixes for 5.10.
Unfortunately, we found some problems with the new READ_PLUS operation
that aren't easy to fix. We've decided to disable this codepath
through a Kconfig option for now, but a series of patches going into
5.11 will clean up the code and fix the issues at the same time. This
seemed like the best way to go about it.
Summary:
- Fix array overflow when flexfiles mirroring is enabled
- Fix rpcrdma_inline_fixup() crash with new LISTXATTRS
- Fix 5 second delay when doing inter-server copy
- Disable READ_PLUS by default"
* tag 'nfs-for-5.10-3' of git://git.linux-nfs.org/projects/anna/linux-nfs:
NFS: Disable READ_PLUS by default
NFSv4.2: Fix 5 seconds delay when doing inter server copy
NFS: Fix rpcrdma_inline_fixup() crash with new LISTXATTRS operation
pNFS/flexfiles: Fix array overflow when flexfiles mirroring is enabled
|
|
We've been seeing failures with xfstests generic/091 and generic/263
when using READ_PLUS. I've made some progress on these issues, and the
tests fail later on but still don't pass. Let's disable READ_PLUS by
default until we can work out what is going on.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
|
|
Since commit b4868b44c5628 ("NFSv4: Wait for stateid updates after
CLOSE/OPEN_DOWNGRADE"), every inter server copy operation suffers 5
seconds delay regardless of the size of the copy. The delay is from
nfs_set_open_stateid_locked when the check by nfs_stateid_is_sequential
fails because the seqid in both nfs4_state and nfs4_stateid are 0.
Fix __nfs42_ssc_open to delay setting of NFS_OPEN_STATE in nfs4_state,
until after the call to update_open_stateid, to indicate this is the 1st
open. This fix is part of a 2 patches, the other patch is the fix in the
source server to return the stateid for COPY_NOTIFY request with seqid 1
instead of 0.
Fixes: ce0887ac96d3 ("NFSD add nfs4 inter ssc to nfsd4_copy")
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
|
|
By switching to an XFS-backed export, I am able to reproduce the
ibcomp worker crash on my client with xfstests generic/013.
For the failing LISTXATTRS operation, xdr_inline_pages() is called
with page_len=12 and buflen=128.
- When ->send_request() is called, rpcrdma_marshal_req() does not
set up a Reply chunk because buflen is smaller than the inline
threshold. Thus rpcrdma_convert_iovs() does not get invoked at
all and the transport's XDRBUF_SPARSE_PAGES logic is not invoked
on the receive buffer.
- During reply processing, rpcrdma_inline_fixup() tries to copy
received data into rq_rcv_buf->pages because page_len is positive.
But there are no receive pages because rpcrdma_marshal_req() never
allocated them.
The result is that the ibcomp worker faults and dies. Sometimes that
causes a visible crash, and sometimes it results in a transport hang
without other symptoms.
RPC/RDMA's XDRBUF_SPARSE_PAGES support is not entirely correct, and
should eventually be fixed or replaced. However, my preference is
that upper-layer operations should explicitly allocate their receive
buffers (using GFP_KERNEL) when possible, rather than relying on
XDRBUF_SPARSE_PAGES.
Reported-by: Olga kornievskaia <kolga@netapp.com>
Suggested-by: Olga kornievskaia <kolga@netapp.com>
Fixes: c10a75145feb ("NFSv4.2: add the extended attribute proc functions.")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Olga kornievskaia <kolga@netapp.com>
Reviewed-by: Frank van der Linden <fllinden@amazon.com>
Tested-by: Olga kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
|
|
In zonefs_file_dio_append(), the pages obtained using
bio_iov_iter_get_pages() are not released on completion of the
REQ_OP_APPEND BIO, nor when bio_iov_iter_get_pages() fails.
Furthermore, a call to bio_put() is missing when
bio_iov_iter_get_pages() fails.
Fix these resource leaks by adding BIO resource release code (bio_put()i
and bio_release_pages()) at the end of the function after the BIO
execution and add a jump to this resource cleanup code in case of
bio_iov_iter_get_pages() failure.
While at it, also fix the call to task_io_account_write() to be passed
the correct BIO size instead of bio_iov_iter_get_pages() return value.
Reported-by: Christoph Hellwig <hch@lst.de>
Fixes: 02ef12a663c7 ("zonefs: use REQ_OP_ZONE_APPEND for sync DIO")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
|
|
There's a memory leak in afs_parse_source() whereby multiple source=
parameters overwrite fc->source in the fs_context struct without freeing
the previously recorded source.
Fix this by only permitting a single source parameter and rejecting with
an error all subsequent ones.
This was caught by syzbot with the kernel memory leak detector, showing
something like the following trace:
unreferenced object 0xffff888114375440 (size 32):
comm "repro", pid 5168, jiffies 4294923723 (age 569.948s)
backtrace:
slab_post_alloc_hook+0x42/0x79
__kmalloc_track_caller+0x125/0x16a
kmemdup_nul+0x24/0x3c
vfs_parse_fs_string+0x5a/0xa1
generic_parse_monolithic+0x9d/0xc5
do_new_mount+0x10d/0x15a
do_mount+0x5f/0x8e
__do_sys_mount+0xff/0x127
do_syscall_64+0x2d/0x3a
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: 13fcc6837049 ("afs: Add fs_context support")
Reported-by: syzbot+86dc6632faaca40133ab@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Pull seq_file fix from Al Viro:
"This fixes a regression introduced in this cycle wrt iov_iter based
variant for reading a seq_file"
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fix return values of seq_read_iter()
|
|
Put file as part of error handling when setting up io ctx to fix
memory leaks like the following one.
BUG: memory leak
unreferenced object 0xffff888101ea2200 (size 256):
comm "syz-executor355", pid 8470, jiffies 4294953658 (age 32.400s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
20 59 03 01 81 88 ff ff 80 87 a8 10 81 88 ff ff Y..............
backtrace:
[<000000002e0a7c5f>] kmem_cache_zalloc include/linux/slab.h:654 [inline]
[<000000002e0a7c5f>] __alloc_file+0x1f/0x130 fs/file_table.c:101
[<000000001a55b73a>] alloc_empty_file+0x69/0x120 fs/file_table.c:151
[<00000000fb22349e>] alloc_file+0x33/0x1b0 fs/file_table.c:193
[<000000006e1465bb>] alloc_file_pseudo+0xb2/0x140 fs/file_table.c:233
[<000000007118092a>] anon_inode_getfile fs/anon_inodes.c:91 [inline]
[<000000007118092a>] anon_inode_getfile+0xaa/0x120 fs/anon_inodes.c:74
[<000000002ae99012>] io_uring_get_fd fs/io_uring.c:9198 [inline]
[<000000002ae99012>] io_uring_create fs/io_uring.c:9377 [inline]
[<000000002ae99012>] io_uring_setup+0x1125/0x1630 fs/io_uring.c:9411
[<000000008280baad>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
[<00000000685d8cf0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Reported-by: syzbot+71c4697e27c99fddcf17@syzkaller.appspotmail.com
Fixes: 0f2122045b94 ("io_uring: don't rely on weak ->files references")
Cc: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
After io_identity_cow() copies an work.identity it wants to copy creds
to the new just allocated id, not the old one. Otherwise it's
akin to req->work.identity->creds = req->work.identity->creds.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
'format_corename()' will splite 'core_pattern' on spaces when it is in
pipe mode, and take helper_argv[0] as the path to usermode executable.
It works fine in most cases.
However, if there is a space between '|' and '/file/path', such as
'| /usr/lib/systemd/systemd-coredump %P %u %g', then helper_argv[0] will
be parsed as '', and users will get a 'Core dump to | disabled'.
It is not friendly to users, as the pattern above was valid previously.
Fix this by ignoring the spaces between '|' and '/file/path'.
Fixes: 315c69261dd3 ("coredump: split pipe command whitespace before expanding template")
Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul Wise <pabs3@bonedaddy.net>
Cc: Jakub Wilk <jwilk@jwilk.net> [https://bugs.debian.org/924398]
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/5fb62870.1c69fb81.8ef5d.af76@mx.google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Pull io_uring fix from Jens Axboe:
"Just a small fix this time, for an issue with 32-bit compat apps and
buffer selection with recvmsg"
* tag 'io_uring-5.10-2020-12-05' of git://git.kernel.dk/linux-block:
io_uring: fix recvmsg setup with compat buf-select
|
|
Pull cifs fixes from Steve French:
"Three smb3 fixes (two for stable) fixing
- a null pointer issue in a DFS error path
- a problem with excessive padding when mounted with "idsfromsid"
causing owner fields to get corrupted
- a more recent problem with compounded reparse point query found in
testing to the Linux kernel server"
* tag '5.10-rc6-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
cifs: refactor create_sd_buf() and and avoid corrupting the buffer
cifs: add NULL check for ses->tcon_ipc
smb3: set COMPOUND_FID to FileID field of subsequent compound request
|
|
When mounting with "idsfromsid" mount option, Azure
corrupted the owner SIDs due to excessive padding
caused by placing the owner fields at the end of the
security descriptor on create. Placing owners at the
front of the security descriptor (rather than the end)
is also safer, as the number of ACEs (that follow it)
are variable.
Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Suggested-by: Rohith Surabattula <rohiths@microsoft.com>
CC: Stable <stable@vger.kernel.org> # v5.8
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
In some scenarios (DFS and BAD_NETWORK_NAME) set_root_set() can be
called with a NULL ses->tcon_ipc.
Signed-off-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
CC: Stable <stable@vger.kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
For an operation compounded with an SMB2 CREATE request, client must set
COMPOUND_FID(0xFFFFFFFFFFFFFFFF) to FileID field of smb2 ioctl.
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Fixes: 2e4564b31b645 ("smb3: add support stat of WSL reparse points for special file types")
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
Pull 9p fixes from Dominique Martinet:
"Restore splice functionality for 9p"
* tag '9p-for-5.10-rc7' of git://github.com/martinetd/linux:
fs: 9p: add generic splice_write file operation
fs: 9p: add generic splice_read file operations
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull gfs2 fixes from Andreas Gruenbacher:
"Various gfs2 fixes"
* tag 'gfs2-v5.10-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Fix deadlock between gfs2_{create_inode,inode_lookup} and delete_work_func
gfs2: Upgrade shared glocks for atime updates
gfs2: Don't freeze the file system during unmount
gfs2: check for empty rgrp tree in gfs2_ri_update
gfs2: set lockdep subclass for iopen glocks
gfs2: Fix deadlock dumping resource group glocks
|
|
The default splice operations got removed recently, add it back to 9p
with iter_file_splice_write like many other filesystems do.
Link: http://lkml.kernel.org/r/1606837496-21717-1-git-send-email-asmadeus@codewreck.org
Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops")
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
|
|
The v9fs file operations were missing the splice_read operations, which
breaks sendfile() of files on such a filesystem. I discovered this while
trying to load an eBPF program using iproute2 inside a 'virtme' environment
which uses 9pfs for the virtual file system. iproute2 relies on sendfile()
with an AF_ALG socket to hash files, which was erroring out in the virtual
environment.
Since generic_file_splice_read() seems to just implement splice_read in
terms of the read_iter operation, I simply added the generic implementation
to the file operations, which fixed the error I was seeing. A quick grep
indicates that this is what most other file systems do as well.
Link: http://lkml.kernel.org/r/20201201135409.55510-1-toke@redhat.com
Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
|
|
In gfs2_create_inode and gfs2_inode_lookup, make sure to cancel any pending
delete work before taking the inode glock. Otherwise, gfs2_cancel_delete_work
may block waiting for delete_work_func to complete, and delete_work_func may
block trying to acquire the inode glock in gfs2_inode_lookup.
Reported-by: Alexander Aring <aahringo@redhat.com>
Fixes: a0e3cc65fa29 ("gfs2: Turn gl_delete into a delayed work")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
|
|
This patch fixes a potential use-after-free bug in
cifs_echo_request().
For instance,
thread 1
--------
cifs_demultiplex_thread()
clean_demultiplex_info()
kfree(server)
thread 2 (workqueue)
--------
apic_timer_interrupt()
smp_apic_timer_interrupt()
irq_exit()
__do_softirq()
run_timer_softirq()
call_timer_fn()
cifs_echo_request() <- use-after-free in server ptr
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
A customer has reported that several files in their multi-threaded app
were left with size of 0 because most of the read(2) calls returned
-EINTR and they assumed no bytes were read. Obviously, they could
have fixed it by simply retrying on -EINTR.
We noticed that most of the -EINTR on read(2) were due to real-time
signals sent by glibc to process wide credential changes (SIGRT_1),
and its signal handler had been established with SA_RESTART, in which
case those calls could have been automatically restarted by the
kernel.
Let the kernel decide to whether or not restart the syscalls when
there is a signal pending in __smb_send_rqst() by returning
-ERESTARTSYS. If it can't, it will return -EINTR anyway.
Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
|
|
__io_compat_recvmsg_copy_hdr() with REQ_F_BUFFER_SELECT reads out iov
len but never assigns it to iov/fast_iov, leaving sr->len with garbage.
Hopefully, following io_buffer_select() truncates it to the selected
buffer size, but the value is still may be under what was specified.
Cc: <stable@vger.kernel.org> # 5.7
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
If the flexfiles mirroring is enabled, then the read code expects to be
able to set pgio->pg_mirror_idx to point to the data server that is
being used for this particular read. However it does not change the
pg_mirror_count because we only need to send a single read.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI fixes from Borislav Petkov:
"More EFI fixes forwarded from Ard Biesheuvel:
- revert efivarfs kmemleak fix again - it was a false positive
- make CONFIG_EFI_EARLYCON depend on CONFIG_EFI explicitly so it does
not pull in other dependencies unnecessarily if CONFIG_EFI is not
set
- defer attempts to load SSDT overrides from EFI vars until after the
efivar layer is up"
* tag 'efi-urgent-for-v5.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi: EFI_EARLYCON should depend on EFI
efivarfs: revert "fix memory leak in efivarfs_create()"
efi/efivars: Set generic ops before loading SSDT
|
|
Pull io_uring fixes from Jens Axboe:
- Out of bounds fix for the cq size cap from earlier this release (Joseph)
- iov_iter type check fix (Pavel)
- Files grab + cancelation fix (Pavel)
* tag 'io_uring-5.10-2020-11-27' of git://git.kernel.dk/linux-block:
io_uring: fix files grab/cancel race
io_uring: fix ITER_BVEC check
io_uring: fix shift-out-of-bounds when round up cq size
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"A few fixes for various warnings that accumulated over past two weeks:
- tree-checker: add missing return values for some errors
- lockdep fixes
- when reading qgroup config and starting quota rescan
- reverse order of quota ioctl lock and VFS freeze lock
- avoid accessing potentially stale fs info during device scan,
reported by syzbot
- add scope NOFS protection around qgroup relation changes
- check for running transaction before flushing qgroups
- fix tracking of new delalloc ranges for some cases"
* tag 'for-5.10-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: fix lockdep splat when enabling and disabling qgroups
btrfs: do nofs allocations when adding and removing qgroup relations
btrfs: fix lockdep splat when reading qgroup config on mount
btrfs: tree-checker: add missing returns after data_ref alignment checks
btrfs: don't access possibly stale fs_info data for printing duplicate device
btrfs: tree-checker: add missing return after error in root_item
btrfs: qgroup: don't commit transaction when we already hold the handle
btrfs: fix missing delalloc new bit for new delalloc ranges
|
|
Commit 20f829999c38 ("gfs2: Rework read and page fault locking") lifted
the glock lock taking from the low-level ->readpage and ->readahead
address space operations to the higher-level ->read_iter file and
->fault vm operations. The glocks are still taken in LM_ST_SHARED mode
only. On filesystems mounted without the noatime option, ->read_iter
sometimes needs to update the atime as well, though. Right now, this
leads to a failed locking mode assertion in gfs2_dirty_inode.
Fix that by introducing a new update_time inode operation. There, if
the glock is held non-exclusively, upgrade it to an exclusive lock.
Reported-by: Alexander Aring <aahringo@redhat.com>
Fixes: 20f829999c38 ("gfs2: Rework read and page fault locking")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
|
|
When one task is in io_uring_cancel_files() and another is doing
io_prep_async_work() a race may happen. That's because after accounting
a request inflight in first call to io_grab_identity() it still may fail
and go to io_identity_cow(), which migh briefly keep dangling
work.identity and not only.
Grab files last, so io_prep_async_work() won't fail if it did get into
->inflight_list.
note: the bug shouldn't exist after making io_uring_cancel_files() not
poking into other tasks' requests.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
GFS2's freeze/thaw mechanism uses a special freeze glock to control its
operation. It does this with a sync glock operation (glops.c) called
freeze_go_sync. When the freeze glock is demoted (glock's do_xmote) the
glops function causes the file system to be frozen. This is intended. However,
GFS2's mount and unmount processes also hold the freeze glock to prevent other
processes, perhaps on different cluster nodes, from mounting the frozen file
system in read-write mode.
Before this patch, there was no check in freeze_go_sync for whether a freeze
in intended or whether the glock demote was caused by a normal unmount.
So it was trying to freeze the file system it's trying to unmount, which
ends up in a deadlock.
This patch adds an additional check to freeze_go_sync so that demotes of the
freeze glock are ignored if they come from the unmount process.
Fixes: 20b329129009 ("gfs2: Fix regression in freeze_go_sync")
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
|
|
If gfs2 tries to mount a (corrupt) file system that has no resource
groups it still tries to set preferences on the first one, which causes
a kernel null pointer dereference. This patch adds a check to function
gfs2_ri_update so this condition is detected and reported back as an
error.
Reported-by: syzbot+e3f23ce40269a4c9053a@syzkaller.appspotmail.com
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
|
|
The memory leak addressed by commit fe5186cf12e3 is a false positive:
all allocations are recorded in a linked list, and freed when the
filesystem is unmounted. This leads to double frees, and as reported
by David, leads to crashes if SLUB is configured to self destruct when
double frees occur.
So drop the redundant kfree() again, and instead, mark the offending
pointer variable so the allocation is ignored by kmemleak.
Cc: Vamshi K Sthambamkadi <vamshi.k.sthambamkadi@gmail.com>
Fixes: fe5186cf12e3 ("efivarfs: fix memory leak in efivarfs_create()")
Reported-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
|
|
Pull cifs fixes from Steve French:
"Four smb3 fixes for stable: one fixes a memleak, the other three
address a problem found with decryption offload that can cause a use
after free"
* tag '5.10-rc5-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
smb3: Handle error case during offload read path
smb3: Avoid Mid pending list corruption
smb3: Call cifs reconnect from demultiplex thread
cifs: fix a memleak with modefromsid
|
|
This patch introduce a new globs attribute to define the subclass of the
glock lockref spinlock. This avoid the following lockdep warning, which
occurs when we lock an inode lock while an iopen lock is held:
============================================
WARNING: possible recursive locking detected
5.10.0-rc3+ #4990 Not tainted
--------------------------------------------
kworker/0:1/12 is trying to acquire lock:
ffff9067d45672d8 (&gl->gl_lockref.lock){+.+.}-{3:3}, at: lockref_get+0x9/0x20
but task is already holding lock:
ffff9067da308588 (&gl->gl_lockref.lock){+.+.}-{3:3}, at: delete_work_func+0x164/0x260
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&gl->gl_lockref.lock);
lock(&gl->gl_lockref.lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by kworker/0:1/12:
#0: ffff9067c1bfdd38 ((wq_completion)delete_workqueue){+.+.}-{0:0}, at: process_one_work+0x1b7/0x540
#1: ffffac594006be70 ((work_completion)(&(&gl->gl_delete)->work)){+.+.}-{0:0}, at: process_one_work+0x1b7/0x540
#2: ffff9067da308588 (&gl->gl_lockref.lock){+.+.}-{3:3}, at: delete_work_func+0x164/0x260
stack backtrace:
CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.10.0-rc3+ #4990
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
Workqueue: delete_workqueue delete_work_func
Call Trace:
dump_stack+0x8b/0xb0
__lock_acquire.cold+0x19e/0x2e3
lock_acquire+0x150/0x410
? lockref_get+0x9/0x20
_raw_spin_lock+0x27/0x40
? lockref_get+0x9/0x20
lockref_get+0x9/0x20
delete_work_func+0x188/0x260
process_one_work+0x237/0x540
worker_thread+0x4d/0x3b0
? process_one_work+0x540/0x540
kthread+0x127/0x140
? __kthread_bind_mask+0x60/0x60
ret_from_fork+0x22/0x30
Suggested-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
|
|
Commit 0e539ca1bbbe ("gfs2: Fix NULL pointer dereference in gfs2_rgrp_dump")
introduced additional locking in gfs2_rgrp_go_dump, which is also used for
dumping resource group glocks via debugfs. However, on that code path, the
glock spin lock is already taken in dump_glock, and taking it again in
gfs2_glock2rgrp leads to deadlock. This can be reproduced with:
$ mkfs.gfs2 -O -p lock_nolock /dev/FOO
$ mount /dev/FOO /mnt/foo
$ touch /mnt/foo/bar
$ cat /sys/kernel/debug/gfs2/FOO/glocks
Fix that by not taking the glock spin lock inside the go_dump callback.
Fixes: 0e539ca1bbbe ("gfs2: Fix NULL pointer dereference in gfs2_rgrp_dump")
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
|
|
iov_iter::type is a bitmask that also keeps direction etc., so it
shouldn't be directly compared against ITER_*. Use proper helper.
Fixes: ff6165b2d7f6 ("io_uring: retain iov_iter state over io_read/io_write calls")
Reported-by: David Howells <dhowells@redhat.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Cc: <stable@vger.kernel.org> # 5.9
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Abaci Fuzz reported a shift-out-of-bounds BUG in io_uring_create():
[ 59.598207] UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13
[ 59.599665] shift exponent 64 is too large for 64-bit type 'long unsigned int'
[ 59.601230] CPU: 0 PID: 963 Comm: a.out Not tainted 5.10.0-rc4+ #3
[ 59.602502] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[ 59.603673] Call Trace:
[ 59.604286] dump_stack+0x107/0x163
[ 59.605237] ubsan_epilogue+0xb/0x5a
[ 59.606094] __ubsan_handle_shift_out_of_bounds.cold+0xb2/0x20e
[ 59.607335] ? lock_downgrade+0x6c0/0x6c0
[ 59.608182] ? rcu_read_lock_sched_held+0xaf/0xe0
[ 59.609166] io_uring_create.cold+0x99/0x149
[ 59.610114] io_uring_setup+0xd6/0x140
[ 59.610975] ? io_uring_create+0x2510/0x2510
[ 59.611945] ? lockdep_hardirqs_on_prepare+0x286/0x400
[ 59.613007] ? syscall_enter_from_user_mode+0x27/0x80
[ 59.614038] ? trace_hardirqs_on+0x5b/0x180
[ 59.615056] do_syscall_64+0x2d/0x40
[ 59.615940] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 59.617007] RIP: 0033:0x7f2bb8a0b239
This is caused by roundup_pow_of_two() if the input entries larger
enough, e.g. 2^32-1. For sq_entries, it will check first and we allow
at most IORING_MAX_ENTRIES, so it is okay. But for cq_entries, we do
round up first, that may overflow and truncate it to 0, which is not
the expected behavior. So check the cq size first and then do round up.
Fixes: 88ec3211e463 ("io_uring: round-up cq size before comparing with rounded sq size")
Reported-by: Abaci Fuzz <abaci@linux.alibaba.com>
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
When running test case btrfs/017 from fstests, lockdep reported the
following splat:
[ 1297.067385] ======================================================
[ 1297.067708] WARNING: possible circular locking dependency detected
[ 1297.068022] 5.10.0-rc4-btrfs-next-73 #1 Not tainted
[ 1297.068322] ------------------------------------------------------
[ 1297.068629] btrfs/189080 is trying to acquire lock:
[ 1297.068929] ffff9f2725731690 (sb_internal#2){.+.+}-{0:0}, at: btrfs_quota_enable+0xaf/0xa70 [btrfs]
[ 1297.069274]
but task is already holding lock:
[ 1297.069868] ffff9f2702b61a08 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_enable+0x3b/0xa70 [btrfs]
[ 1297.070219]
which lock already depends on the new lock.
[ 1297.071131]
the existing dependency chain (in reverse order) is:
[ 1297.071721]
-> #1 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}:
[ 1297.072375] lock_acquire+0xd8/0x490
[ 1297.072710] __mutex_lock+0xa3/0xb30
[ 1297.073061] btrfs_qgroup_inherit+0x59/0x6a0 [btrfs]
[ 1297.073421] create_subvol+0x194/0x990 [btrfs]
[ 1297.073780] btrfs_mksubvol+0x3fb/0x4a0 [btrfs]
[ 1297.074133] __btrfs_ioctl_snap_create+0x119/0x1a0 [btrfs]
[ 1297.074498] btrfs_ioctl_snap_create+0x58/0x80 [btrfs]
[ 1297.074872] btrfs_ioctl+0x1a90/0x36f0 [btrfs]
[ 1297.075245] __x64_sys_ioctl+0x83/0xb0
[ 1297.075617] do_syscall_64+0x33/0x80
[ 1297.075993] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1297.076380]
-> #0 (sb_internal#2){.+.+}-{0:0}:
[ 1297.077166] check_prev_add+0x91/0xc60
[ 1297.077572] __lock_acquire+0x1740/0x3110
[ 1297.077984] lock_acquire+0xd8/0x490
[ 1297.078411] start_transaction+0x3c5/0x760 [btrfs]
[ 1297.078853] btrfs_quota_enable+0xaf/0xa70 [btrfs]
[ 1297.079323] btrfs_ioctl+0x2c60/0x36f0 [btrfs]
[ 1297.079789] __x64_sys_ioctl+0x83/0xb0
[ 1297.080232] do_syscall_64+0x33/0x80
[ 1297.080680] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1297.081139]
other info that might help us debug this:
[ 1297.082536] Possible unsafe locking scenario:
[ 1297.083510] CPU0 CPU1
[ 1297.084005] ---- ----
[ 1297.084500] lock(&fs_info->qgroup_ioctl_lock);
[ 1297.084994] lock(sb_internal#2);
[ 1297.085485] lock(&fs_info->qgroup_ioctl_lock);
[ 1297.085974] lock(sb_internal#2);
[ 1297.086454]
*** DEADLOCK ***
[ 1297.087880] 3 locks held by btrfs/189080:
[ 1297.088324] #0: ffff9f2725731470 (sb_writers#14){.+.+}-{0:0}, at: btrfs_ioctl+0xa73/0x36f0 [btrfs]
[ 1297.088799] #1: ffff9f2702b60cc0 (&fs_info->subvol_sem){++++}-{3:3}, at: btrfs_ioctl+0x1f4d/0x36f0 [btrfs]
[ 1297.089284] #2: ffff9f2702b61a08 (&fs_info->qgroup_ioctl_lock){+.+.}-{3:3}, at: btrfs_quota_enable+0x3b/0xa70 [btrfs]
[ 1297.089771]
stack backtrace:
[ 1297.090662] CPU: 5 PID: 189080 Comm: btrfs Not tainted 5.10.0-rc4-btrfs-next-73 #1
[ 1297.091132] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 1297.092123] Call Trace:
[ 1297.092629] dump_stack+0x8d/0xb5
[ 1297.093115] check_noncircular+0xff/0x110
[ 1297.093596] check_prev_add+0x91/0xc60
[ 1297.094076] ? kvm_clock_read+0x14/0x30
[ 1297.094553] ? kvm_sched_clock_read+0x5/0x10
[ 1297.095029] __lock_acquire+0x1740/0x3110
[ 1297.095510] lock_acquire+0xd8/0x490
[ 1297.095993] ? btrfs_quota_enable+0xaf/0xa70 [btrfs]
[ 1297.096476] start_transaction+0x3c5/0x760 [btrfs]
[ 1297.096962] ? btrfs_quota_enable+0xaf/0xa70 [btrfs]
[ 1297.097451] btrfs_quota_enable+0xaf/0xa70 [btrfs]
[ 1297.097941] ? btrfs_ioctl+0x1f4d/0x36f0 [btrfs]
[ 1297.098429] btrfs_ioctl+0x2c60/0x36f0 [btrfs]
[ 1297.098904] ? do_user_addr_fault+0x20c/0x430
[ 1297.099382] ? kvm_clock_read+0x14/0x30
[ 1297.099854] ? kvm_sched_clock_read+0x5/0x10
[ 1297.100328] ? sched_clock+0x5/0x10
[ 1297.100801] ? sched_clock_cpu+0x12/0x180
[ 1297.101272] ? __x64_sys_ioctl+0x83/0xb0
[ 1297.101739] __x64_sys_ioctl+0x83/0xb0
[ 1297.102207] do_syscall_64+0x33/0x80
[ 1297.102673] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 1297.103148] RIP: 0033:0x7f773ff65d87
This is because during the quota enable ioctl we lock first the mutex
qgroup_ioctl_lock and then start a transaction, and starting a transaction
acquires a fs freeze semaphore (at the VFS level). However, every other
code path, except for the quota disable ioctl path, we do the opposite:
we start a transaction and then lock the mutex.
So fix this by making the quota enable and disable paths to start the
transaction without having the mutex locked, and then, after starting the
transaction, lock the mutex and check if some other task already enabled
or disabled the quotas, bailing with success if that was the case.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
|
When adding or removing a qgroup relation we are doing a GFP_KERNEL
allocation which is not safe because we are holding a transaction
handle open and that can make us deadlock if the allocator needs to
recurse into the filesystem. So just surround those calls with a
nofs context.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
