pm24.git/fs/fuse/dev.c, branch v5.6

fuse: fix stack use after return

2020-02-13T08:16:07Z

Normal, synchronous requests will have their args allocated on the stack. After the FR_FINISHED bit is set by receiving the reply from the userspace fuse server, the originating task may return and reuse the stack frame, resulting in an Oops if the args structure is dereferenced. Fix by setting a flag in the request itself upon initializing, indicating whether it has an asynchronous ->end() callback. Reported-by: Kyle Sanderson Reported-by: Michael Stapelberg Fixes: 2b319d1f6f92 ("fuse: don't dereference req->args on finished request") Cc: # v5.4 Tested-by: Michael Stapelberg Signed-off-by: Miklos Szeredi

pipe: Fix iteration end check in fuse_dev_splice_write()

2019-12-06T21:57:04Z

Fix the iteration end check in fuse_dev_splice_write(). The iterator position can only be compared with == or != since wrappage may be involved. Fixes: 8cefc107ca54 ("pipe: Use head and tail pointers for the ring, not cursor and length") Reported-by: Linus Torvalds Signed-off-by: David Howells Signed-off-by: Linus Torvalds

Merge tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground

2019-12-01T21:46:15Z

Pull removal of most of fs/compat_ioctl.c from Arnd Bergmann: "As part of the cleanup of some remaining y2038 issues, I came to fs/compat_ioctl.c, which still has a couple of commands that need support for time64_t. In completely unrelated work, I spent time on cleaning up parts of this file in the past, moving things out into drivers instead. After Al Viro reviewed an earlier version of this series and did a lot more of that cleanup, I decided to try to completely eliminate the rest of it and move it all into drivers. This series incorporates some of Al's work and many patches of my own, but in the end stops short of actually removing the last part, which is the scsi ioctl handlers. I have patches for those as well, but they need more testing or possibly a rewrite" * tag 'compat-ioctl-5.5' of git://git.kernel.org:/pub/scm/linux/kernel/git/arnd/playground: (42 commits) scsi: sd: enable compat ioctls for sed-opal pktcdvd: add compat_ioctl handler compat_ioctl: move SG_GET_REQUEST_TABLE handling compat_ioctl: ppp: move simple commands into ppp_generic.c compat_ioctl: handle PPPIOCGIDLE for 64-bit time_t compat_ioctl: move PPPIOCSCOMPRESS to ppp_generic compat_ioctl: unify copy-in of ppp filters tty: handle compat PPP ioctls compat_ioctl: move SIOCOUTQ out of compat_ioctl.c compat_ioctl: handle SIOCOUTQNSD af_unix: add compat_ioctl support compat_ioctl: reimplement SG_IO handling compat_ioctl: move WDIOC handling into wdt drivers fs: compat_ioctl: move FITRIM emulation into file systems gfs2: add compat_ioctl support compat_ioctl: remove unused convert_in_user macro compat_ioctl: remove last RAID handling code compat_ioctl: remove /dev/raw ioctl translation compat_ioctl: remove PCI ioctl translation compat_ioctl: remove joystick ioctl translation ...

Merge tag 'notifications-pipe-prep-20191115' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

2019-11-30T22:12:13Z

Pull pipe rework from David Howells: "This is my set of preparatory patches for building a general notification queue on top of pipes. It makes a number of significant changes: - It removes the nr_exclusive argument from __wake_up_sync_key() as this is always 1. This prepares for the next step: - Adds wake_up_interruptible_sync_poll_locked() so that poll can be woken up from a function that's holding the poll waitqueue spinlock. - Change the pipe buffer ring to be managed in terms of unbounded head and tail indices rather than bounded index and length. This means that reading the pipe only needs to modify one index, not two. - A selection of helper functions are provided to query the state of the pipe buffer, plus a couple to apply updates to the pipe indices. - The pipe ring is allowed to have kernel-reserved slots. This allows many notification messages to be spliced in by the kernel without allowing userspace to pin too many pages if it writes to the same pipe. - Advance the head and tail indices inside the pipe waitqueue lock and use wake_up_interruptible_sync_poll_locked() to poke poll without having to take the lock twice. - Rearrange pipe_write() to preallocate the buffer it is going to write into and then drop the spinlock. This allows kernel notifications to then be added the ring whilst it is filling the buffer it allocated. The read side is stalled because the pipe mutex is still held. - Don't wake up readers on a pipe if there was already data in it when we added more. - Don't wake up writers on a pipe if the ring wasn't full before we removed a buffer" * tag 'notifications-pipe-prep-20191115' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: pipe: Remove sync on wake_ups pipe: Increase the writer-wakeup threshold to reduce context-switch count pipe: Check for ring full inside of the spinlock in pipe_write() pipe: Remove redundant wakeup from pipe_write() pipe: Rearrange sequence in pipe_write() to preallocate slot pipe: Conditionalise wakeup in pipe_read() pipe: Advance tail pointer inside of wait spinlock in pipe_read() pipe: Allow pipes to have kernel-reserved slots pipe: Use head and tail pointers for the ring, not cursor and length Add wake_up_interruptible_sync_poll_locked() Remove the nr_exclusive argument from __wake_up_sync_key() pipe: Reduce #inclusion of pipe_fs_i.h

pipe: Allow pipes to have kernel-reserved slots

2019-11-15T16:22:54Z

Split pipe->ring_size into two numbers: (1) pipe->ring_size - indicates the hard size of the pipe ring. (2) pipe->max_usage - indicates the maximum number of pipe ring slots that userspace orchestrated events can fill. This allows for a pipe that is both writable by the general kernel notification facility and by userspace, allowing plenty of ring space for notifications to be added whilst preventing userspace from being able to pin too much unswappable kernel space. Signed-off-by: David Howells

pipe: Use head and tail pointers for the ring, not cursor and length

2019-10-31T15:12:34Z

Convert pipes to use head and tail pointers for the buffer ring rather than pointer and length as the latter requires two atomic ops to update (or a combined op) whereas the former only requires one. (1) The head pointer is the point at which production occurs and points to the slot in which the next buffer will be placed. This is equivalent to pipe->curbuf + pipe->nrbufs. The head pointer belongs to the write-side. (2) The tail pointer is the point at which consumption occurs. It points to the next slot to be consumed. This is equivalent to pipe->curbuf. The tail pointer belongs to the read-side. (3) head and tail are allowed to run to UINT_MAX and wrap naturally. They are only masked off when the array is being accessed, e.g.: pipe->bufs[head & mask] This means that it is not necessary to have a dead slot in the ring as head == tail isn't ambiguous. (4) The ring is empty if "head == tail". A helper, pipe_empty(), is provided for this. (5) The occupancy of the ring is "head - tail". A helper, pipe_occupancy(), is provided for this. (6) The number of free slots in the ring is "pipe->ring_size - occupancy". A helper, pipe_space_for_user() is provided to indicate how many slots userspace may use. (7) The ring is full if "head - tail >= pipe->ring_size". A helper, pipe_full(), is provided for this. Signed-off-by: David Howells

compat_ioctl: move more drivers to compat_ptr_ioctl

2019-10-23T15:23:44Z

The .ioctl and .compat_ioctl file operations have the same prototype so they can both point to the same function, which works great almost all the time when all the commands are compatible. One exception is the s390 architecture, where a compat pointer is only 31 bit wide, and converting it into a 64-bit pointer requires calling compat_ptr(). Most drivers here will never run in s390, but since we now have a generic helper for it, it's easy enough to use it consistently. I double-checked all these drivers to ensure that all ioctl arguments are used as pointers or are ignored, but are not interpreted as integer values. Acked-by: Jason Gunthorpe Acked-by: Daniel Vetter Acked-by: Mauro Carvalho Chehab Acked-by: Greg Kroah-Hartman Acked-by: David Sterba Acked-by: Darren Hart (VMware) Acked-by: Jonathan Cameron Acked-by: Bjorn Andersson Acked-by: Dan Williams Signed-off-by: Arnd Bergmann

fuse: don't dereference req->args on finished request

2019-10-21T07:11:40Z

Move the check for async request after check for the request being already finished and done with. Reported-by: syzbot+ae0bb7aae3de6b4594e2@syzkaller.appspotmail.com Fixes: d49937749fef ("fuse: stop copying args to fuse_req") Signed-off-by: Miklos Szeredi

fuse: Make fuse_args_to_req static

2019-09-24T13:28:02Z

Fix sparse warning: fs/fuse/dev.c:468:6: warning: symbol 'fuse_args_to_req' was not declared. Should it be static? Reported-by: Hulk Robot Signed-off-by: YueHaibing Fixes: 68583165f962 ("fuse: add pages to fuse_args") Signed-off-by: Miklos Szeredi

fuse: unexport fuse_put_request

2019-09-24T13:28:01Z

This function has been made static, which now causes a compile-time warning: WARNING: "fuse_put_request" [vmlinux] is a static EXPORT_SYMBOL_GPL Remove the unneeded export. Fixes: 66abc3599c3c ("fuse: unexport request ops") Signed-off-by: Arnd Bergmann Reviewed-by: Stefan Hajnoczi Signed-off-by: Miklos Szeredi