linux/io_uring
Jens Axboe 18414a4a2e io_uring/net: assign kmsg inq/flags before buffer selection
syzbot reports that recv is using an uninitialized value:

=====================================================
BUG: KMSAN: uninit-value in io_req_cqe_overflow io_uring/io_uring.c:810 [inline]
BUG: KMSAN: uninit-value in io_req_complete_post io_uring/io_uring.c:937 [inline]
BUG: KMSAN: uninit-value in io_issue_sqe+0x1f1b/0x22c0 io_uring/io_uring.c:1763
 io_req_cqe_overflow io_uring/io_uring.c:810 [inline]
 io_req_complete_post io_uring/io_uring.c:937 [inline]
 io_issue_sqe+0x1f1b/0x22c0 io_uring/io_uring.c:1763
 io_wq_submit_work+0xa17/0xeb0 io_uring/io_uring.c:1860
 io_worker_handle_work+0xc04/0x2000 io_uring/io-wq.c:597
 io_wq_worker+0x447/0x1410 io_uring/io-wq.c:651
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was stored to memory at:
 io_req_set_res io_uring/io_uring.h:215 [inline]
 io_recv_finish+0xf10/0x1560 io_uring/net.c:861
 io_recv+0x12ec/0x1ea0 io_uring/net.c:1175
 io_issue_sqe+0x429/0x22c0 io_uring/io_uring.c:1751
 io_wq_submit_work+0xa17/0xeb0 io_uring/io_uring.c:1860
 io_worker_handle_work+0xc04/0x2000 io_uring/io-wq.c:597
 io_wq_worker+0x447/0x1410 io_uring/io-wq.c:651
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:3877 [inline]
 slab_alloc_node mm/slub.c:3918 [inline]
 __do_kmalloc_node mm/slub.c:4038 [inline]
 __kmalloc+0x6e4/0x1060 mm/slub.c:4052
 kmalloc include/linux/slab.h:632 [inline]
 io_alloc_async_data+0xc0/0x220 io_uring/io_uring.c:1662
 io_msg_alloc_async io_uring/net.c:166 [inline]
 io_recvmsg_prep_setup io_uring/net.c:725 [inline]
 io_recvmsg_prep+0xbe8/0x1a20 io_uring/net.c:806
 io_init_req io_uring/io_uring.c:2135 [inline]
 io_submit_sqe io_uring/io_uring.c:2182 [inline]
 io_submit_sqes+0x1135/0x2f10 io_uring/io_uring.c:2335
 __do_sys_io_uring_enter io_uring/io_uring.c:3246 [inline]
 __se_sys_io_uring_enter+0x40f/0x3c80 io_uring/io_uring.c:3183
 __x64_sys_io_uring_enter+0x11f/0x1a0 io_uring/io_uring.c:3183
 x64_sys_call+0x2c0/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:427
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

which appears to be io_recv_finish() reading kmsg->msg.msg_inq to decide
if it needs to set IORING_CQE_F_SOCK_NONEMPTY or not. If the recv is
entered with buffer selection, but no buffer is available, then we jump
error path which calls io_recv_finish() without having assigned
kmsg->msg_inq. This might cause an errant setting of the NONEMPTY flag
for a request get gets errored with -ENOBUFS.

Reported-by: syzbot+b1647099e82b3b349fbf@syzkaller.appspotmail.com
Fixes: 4a3223f7bf ("io_uring/net: switch io_recv() to using io_async_msghdr")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-30 14:04:37 -06:00
..
advise.c
advise.h
alloc_cache.h io_uring/alloc_cache: switch to array based caching 2024-04-15 08:10:25 -06:00
cancel.c io_uring: fix warnings on shadow variables 2024-04-15 08:10:26 -06:00
cancel.h
epoll.c
epoll.h
fdinfo.c io_uring: fix warnings on shadow variables 2024-04-15 08:10:26 -06:00
fdinfo.h
filetable.c io_uring/filetable: don't unnecessarily clear/reset bitmap 2024-05-08 08:27:45 -06:00
filetable.h
fs.c
fs.h
futex.c io_uring/alloc_cache: switch to array based caching 2024-04-15 08:10:25 -06:00
futex.h io_uring/alloc_cache: switch to array based caching 2024-04-15 08:10:25 -06:00
io_uring.c io_uring: remove checks for NULL 'sq_offset' 2024-05-22 11:13:44 -06:00
io_uring.h io_uring/rw: reinstate thread check for retries 2024-04-25 09:04:32 -06:00
io-wq.c io_uring/io-wq: Use set_bit() and test_bit() at worker->flags 2024-05-07 13:17:19 -06:00
io-wq.h
kbuf.c io_uring/kbuf: add helpers for getting/peeking multiple buffers 2024-04-22 11:26:01 -06:00
kbuf.h io_uring/kbuf: add helpers for getting/peeking multiple buffers 2024-04-22 11:26:01 -06:00
Makefile io_uring: move mapping/allocation helpers to a separate file 2024-04-15 08:10:26 -06:00
memmap.c io_uring: don't attempt to mmap larger than what the user asks for 2024-05-29 09:53:14 -06:00
memmap.h io_uring: move mapping/allocation helpers to a separate file 2024-04-15 08:10:26 -06:00
msg_ring.c io_uring/msg_ring: cleanup posting to IOPOLL vs !IOPOLL ring 2024-05-01 17:13:51 -06:00
msg_ring.h
napi.c
napi.h
net.c io_uring/net: assign kmsg inq/flags before buffer selection 2024-05-30 14:04:37 -06:00
net.h io_uring/alloc_cache: switch to array based caching 2024-04-15 08:10:25 -06:00
nop.c io_uring: support to inject result for NOP 2024-05-10 06:09:45 -06:00
nop.h
notif.c io_uring/notif: disable LAZY_WAKE for linked notifs 2024-04-30 13:06:27 -06:00
notif.h io_uring/notif: implement notification stacking 2024-04-22 19:31:18 -06:00
opdef.c io_uring/rw: Free iovec before cleaning async data 2024-05-30 08:33:01 -06:00
opdef.h io_uring: drop ->prep_async() 2024-04-15 08:10:25 -06:00
openclose.c
openclose.h
poll.c io_uring/alloc_cache: switch to array based caching 2024-04-15 08:10:25 -06:00
poll.h io_uring/poll: shrink alloc cache size to 32 2024-04-15 08:10:25 -06:00
refs.h io_uring: kill dead code in io_req_complete_post 2024-04-15 08:10:26 -06:00
register.c io_uring: fix warnings on shadow variables 2024-04-15 08:10:26 -06:00
register.h
rsrc.c io_uring: move mapping/allocation helpers to a separate file 2024-04-15 08:10:26 -06:00
rsrc.h io_uring: remove io_req_put_rsrc_locked() 2024-04-15 08:10:26 -06:00
rw.c Assorted commits that had missed the last merge window... 2024-05-21 13:11:44 -07:00
rw.h io_uring/alloc_cache: switch to array based caching 2024-04-15 08:10:25 -06:00
slist.h
splice.c
splice.h
sqpoll.c io_uring/sqpoll: ensure that normal task_work is also run timely 2024-05-21 13:41:14 -06:00
sqpoll.h
statx.c
statx.h
sync.c
sync.h
tctx.c
tctx.h
timeout.c io_uring/timeout: remove duplicate initialization of the io_timeout list. 2024-04-15 08:10:27 -06:00
timeout.h
truncate.c
truncate.h
uring_cmd.c io_uring: separate header for exported net bits 2024-04-15 08:10:26 -06:00
uring_cmd.h io_uring/alloc_cache: switch to array based caching 2024-04-15 08:10:25 -06:00
waitid.c io_uring: remove struct io_tw_state::locked 2024-04-15 08:10:24 -06:00
waitid.h
xattr.c
xattr.h