From ea010070d0a7497253d5a6f919f6dd107450b31a Mon Sep 17 00:00:00 2001 From: shamir rabinovitch Date: Sun, 16 Dec 2018 09:01:08 +0200 Subject: net/rds: fix warn in rds_message_alloc_sgs redundant copy_from_user in rds_sendmsg system call expose rds to issue where rds_rdma_extra_size walk the rds iovec and and calculate the number pf pages (sgs) it need to add to the tail of rds message and later rds_cmsg_rdma_args copy the rds iovec again and re calculate the same number and get different result causing WARN_ON in rds_message_alloc_sgs. fix this by doing the copy_from_user only once per rds_sendmsg system call. When issue occur the below dump is seen: WARNING: CPU: 0 PID: 19789 at net/rds/message.c:316 rds_message_alloc_sgs+0x10c/0x160 net/rds/message.c:316 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 19789 Comm: syz-executor827 Not tainted 4.19.0-next-20181030+ #101 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 panic+0x2ad/0x55c kernel/panic.c:188 __warn.cold.8+0x20/0x45 kernel/panic.c:540 report_bug+0x254/0x2d0 lib/bug.c:186 fixup_bug arch/x86/kernel/traps.c:178 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:271 do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:290 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:969 RIP: 0010:rds_message_alloc_sgs+0x10c/0x160 net/rds/message.c:316 Code: c0 74 04 3c 03 7e 6c 44 01 ab 78 01 00 00 e8 2b 9e 35 fa 4c 89 e0 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 14 9e 35 fa <0f> 0b 31 ff 44 89 ee e8 18 9f 35 fa 45 85 ed 75 1b e8 fe 9d 35 fa RSP: 0018:ffff8801c51b7460 EFLAGS: 00010293 RAX: ffff8801bc412080 RBX: ffff8801d7bf4040 RCX: ffffffff8749c9e6 RDX: 0000000000000000 RSI: ffffffff8749ca5c RDI: 0000000000000004 RBP: ffff8801c51b7490 R08: ffff8801bc412080 R09: ffffed003b5c5b67 R10: ffffed003b5c5b67 R11: ffff8801dae2db3b R12: 0000000000000000 R13: 000000000007165c R14: 000000000007165c R15: 0000000000000005 rds_cmsg_rdma_args+0x82d/0x1510 net/rds/rdma.c:623 rds_cmsg_send net/rds/send.c:971 [inline] rds_sendmsg+0x19a2/0x3180 net/rds/send.c:1273 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:632 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2117 __sys_sendmsg+0x11d/0x280 net/socket.c:2155 __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x44a859 Code: e8 dc e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 6b cb fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f1d4710ada8 EFLAGS: 00000297 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000006dcc28 RCX: 000000000044a859 RDX: 0000000000000000 RSI: 0000000020001600 RDI: 0000000000000003 RBP: 00000000006dcc20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000297 R12: 00000000006dcc2c R13: 646e732f7665642f R14: 00007f1d4710b9c0 R15: 00000000006dcd2c Kernel Offset: disabled Rebooting in 86400 seconds.. Reported-by: syzbot+26de17458aeda9d305d8@syzkaller.appspotmail.com Acked-by: Santosh Shilimkar Signed-off-by: shamir rabinovitch Signed-off-by: David S. Miller --- net/rds/rdma.c | 63 +++++++++++++++++++++++++++++----------------------------- 1 file changed, 32 insertions(+), 31 deletions(-) (limited to 'net/rds/rdma.c') diff --git a/net/rds/rdma.c b/net/rds/rdma.c index 98237feb607a..e1965d9cbcf8 100644 --- a/net/rds/rdma.c +++ b/net/rds/rdma.c @@ -517,9 +517,10 @@ static int rds_rdma_pages(struct rds_iovec iov[], int nr_iovecs) return tot_pages; } -int rds_rdma_extra_size(struct rds_rdma_args *args) +int rds_rdma_extra_size(struct rds_rdma_args *args, + struct rds_iov_vector *iov) { - struct rds_iovec vec; + struct rds_iovec *vec; struct rds_iovec __user *local_vec; int tot_pages = 0; unsigned int nr_pages; @@ -530,13 +531,23 @@ int rds_rdma_extra_size(struct rds_rdma_args *args) if (args->nr_local == 0) return -EINVAL; + iov->iov = kcalloc(args->nr_local, + sizeof(struct rds_iovec), + GFP_KERNEL); + if (!iov->iov) + return -ENOMEM; + + vec = &iov->iov[0]; + + if (copy_from_user(vec, local_vec, args->nr_local * + sizeof(struct rds_iovec))) + return -EFAULT; + iov->len = args->nr_local; + /* figure out the number of pages in the vector */ - for (i = 0; i < args->nr_local; i++) { - if (copy_from_user(&vec, &local_vec[i], - sizeof(struct rds_iovec))) - return -EFAULT; + for (i = 0; i < args->nr_local; i++, vec++) { - nr_pages = rds_pages_in_vec(&vec); + nr_pages = rds_pages_in_vec(vec); if (nr_pages == 0) return -EINVAL; @@ -558,15 +569,15 @@ int rds_rdma_extra_size(struct rds_rdma_args *args) * Extract all arguments and set up the rdma_op */ int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm, - struct cmsghdr *cmsg) + struct cmsghdr *cmsg, + struct rds_iov_vector *vec) { struct rds_rdma_args *args; struct rm_rdma_op *op = &rm->rdma; int nr_pages; unsigned int nr_bytes; struct page **pages = NULL; - struct rds_iovec iovstack[UIO_FASTIOV], *iovs = iovstack; - int iov_size; + struct rds_iovec *iovs; unsigned int i, j; int ret = 0; @@ -586,31 +597,23 @@ int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm, goto out_ret; } - /* Check whether to allocate the iovec area */ - iov_size = args->nr_local * sizeof(struct rds_iovec); - if (args->nr_local > UIO_FASTIOV) { - iovs = sock_kmalloc(rds_rs_to_sk(rs), iov_size, GFP_KERNEL); - if (!iovs) { - ret = -ENOMEM; - goto out_ret; - } + if (vec->len != args->nr_local) { + ret = -EINVAL; + goto out_ret; } - if (copy_from_user(iovs, (struct rds_iovec __user *)(unsigned long) args->local_vec_addr, iov_size)) { - ret = -EFAULT; - goto out; - } + iovs = vec->iov; nr_pages = rds_rdma_pages(iovs, args->nr_local); if (nr_pages < 0) { ret = -EINVAL; - goto out; + goto out_ret; } pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL); if (!pages) { ret = -ENOMEM; - goto out; + goto out_ret; } op->op_write = !!(args->flags & RDS_RDMA_READWRITE); @@ -623,7 +626,7 @@ int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm, op->op_sg = rds_message_alloc_sgs(rm, nr_pages); if (!op->op_sg) { ret = -ENOMEM; - goto out; + goto out_pages; } if (op->op_notify || op->op_recverr) { @@ -635,7 +638,7 @@ int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm, op->op_notifier = kmalloc(sizeof(struct rds_notifier), GFP_KERNEL); if (!op->op_notifier) { ret = -ENOMEM; - goto out; + goto out_pages; } op->op_notifier->n_user_token = args->user_token; op->op_notifier->n_status = RDS_RDMA_SUCCESS; @@ -681,7 +684,7 @@ int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm, */ ret = rds_pin_pages(iov->addr, nr, pages, !op->op_write); if (ret < 0) - goto out; + goto out_pages; else ret = 0; @@ -714,13 +717,11 @@ int rds_cmsg_rdma_args(struct rds_sock *rs, struct rds_message *rm, nr_bytes, (unsigned int) args->remote_vec.bytes); ret = -EINVAL; - goto out; + goto out_pages; } op->op_bytes = nr_bytes; -out: - if (iovs != iovstack) - sock_kfree_s(rds_rs_to_sk(rs), iovs, iov_size); +out_pages: kfree(pages); out_ret: if (ret) -- cgit v1.2.3-70-g09d2