[syzbot] KASAN: use-after-free Read in add_wait_queue

[syzbot] KASAN: use-after-free Read in add_wait_queue

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    8565d64430f8 Merge tag 'bounds-fixes-v5.18-rc1' of git://g..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=179570b5700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=89040bbe61f60a52
dashboard link: https://syzkaller.appspot.com/bug?extid=950cee6d91e62329be2c
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+950cee6d91e62329be2c@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in __add_wait_queue include/linux/wait.h:177 [inline]
BUG: KASAN: use-after-free in add_wait_queue+0x1c0/0x260 kernel/sched/wait.c:24
Read of size 4 at addr ffff888077adca98 by task syz-executor.3/4398

CPU: 1 PID: 4398 Comm: syz-executor.3 Tainted: G        W         5.17.0-syzkaller-01402-g8565d64430f8 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0x8d/0x303 mm/kasan/report.c:255
 __kasan_report mm/kasan/report.c:442 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
 __add_wait_queue include/linux/wait.h:177 [inline]
 add_wait_queue+0x1c0/0x260 kernel/sched/wait.c:24
 __io_queue_proc+0x18c/0x6f0 fs/io_uring.c:6131
 poll_wait include/linux/poll.h:49 [inline]
 n_tty_poll+0x76/0x8a0 drivers/tty/n_tty.c:2322
 tty_poll+0x139/0x1b0 drivers/tty/tty_io.c:2212
 vfs_poll include/linux/poll.h:88 [inline]
 __io_arm_poll_handler+0x397/0xc00 fs/io_uring.c:6165
 io_arm_poll_handler+0x42c/0x940 fs/io_uring.c:6257
 io_queue_sqe_arm_apoll+0x6d/0x430 fs/io_uring.c:7499
 __io_queue_sqe fs/io_uring.c:7541 [inline]
 io_queue_sqe fs/io_uring.c:7568 [inline]
 io_submit_sqe fs/io_uring.c:7776 [inline]
 io_submit_sqes+0x7dda/0x9310 fs/io_uring.c:7882
 __do_sys_io_uring_enter+0x9f1/0x1520 fs/io_uring.c:10924
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f6573120049
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6571a95168 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007f6573232f60 RCX: 00007f6573120049
RDX: 0000000000000000 RSI: 0000000000001261 RDI: 0000000000000004
RBP: 00007f657317a08d R08: 0000000000000000 R09: 0000000030000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe760b3a3f R14: 00007f6571a95300 R15: 0000000000022000
 </TASK>

Allocated by task 4386:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:436 [inline]
 ____kasan_kmalloc mm/kasan/common.c:515 [inline]
 ____kasan_kmalloc mm/kasan/common.c:474 [inline]
 __kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:524
 kasan_kmalloc include/linux/kasan.h:249 [inline]
 kmem_cache_alloc_trace+0x1ea/0x4a0 mm/slab.c:3567
 kmalloc include/linux/slab.h:581 [inline]
 io_arm_poll_handler+0x39d/0x940 fs/io_uring.c:6248
 io_queue_sqe_arm_apoll+0x6d/0x430 fs/io_uring.c:7499
 __io_queue_sqe fs/io_uring.c:7541 [inline]
 io_queue_sqe fs/io_uring.c:7568 [inline]
 io_submit_sqe fs/io_uring.c:7776 [inline]
 io_submit_sqes+0x7dda/0x9310 fs/io_uring.c:7882
 __do_sys_io_uring_enter+0x9f1/0x1520 fs/io_uring.c:10924
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 4061:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:45
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free+0xff/0x140 mm/kasan/common.c:328
 kasan_slab_free include/linux/kasan.h:215 [inline]
 __cache_free mm/slab.c:3437 [inline]
 kfree+0xf8/0x2b0 mm/slab.c:3794
 io_flush_apoll_cache fs/io_uring.c:10038 [inline]
 io_ring_ctx_free fs/io_uring.c:10064 [inline]
 io_ring_exit_work+0x7f7/0x1053 fs/io_uring.c:10244
 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307
 worker_thread+0x657/0x1110 kernel/workqueue.c:2454
 kthread+0x2e9/0x3a0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

The buggy address belongs to the object at ffff888077adca80
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 24 bytes inside of
 96-byte region [ffff888077adca80, ffff888077adcae0)
The buggy address belongs to the page:
page:ffffea0001deb700 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x77adc
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea00007d2088 ffffea00004b7bc8 ffff888010c40300
raw: 0000000000000000 ffff888077adc000 0000000100000020 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x342220(__GFP_HIGH|__GFP_ATOMIC|__GFP_NOWARN|__GFP_COMP|__GFP_HARDWALL|__GFP_THISNODE), pid 3842, ts 194269929651, free_ts 193491488751
 prep_new_page mm/page_alloc.c:2434 [inline]
 get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389
 __alloc_pages_node include/linux/gfp.h:572 [inline]
 kmem_getpages mm/slab.c:1378 [inline]
 cache_grow_begin+0x75/0x390 mm/slab.c:2584
 cache_alloc_refill+0x27f/0x380 mm/slab.c:2957
 ____cache_alloc mm/slab.c:3040 [inline]
 ____cache_alloc mm/slab.c:3023 [inline]
 __do_cache_alloc mm/slab.c:3267 [inline]
 slab_alloc mm/slab.c:3308 [inline]
 kmem_cache_alloc_trace+0x380/0x4a0 mm/slab.c:3565
 kmalloc include/linux/slab.h:581 [inline]
 io_arm_poll_handler+0x39d/0x940 fs/io_uring.c:6248
 io_queue_sqe_arm_apoll+0x6d/0x430 fs/io_uring.c:7499
 __io_queue_sqe fs/io_uring.c:7541 [inline]
 io_queue_sqe fs/io_uring.c:7568 [inline]
 io_submit_sqe fs/io_uring.c:7776 [inline]
 io_submit_sqes+0x7dda/0x9310 fs/io_uring.c:7882
 __do_sys_io_uring_enter+0x9f1/0x1520 fs/io_uring.c:10924
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1352 [inline]
 free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1404
 free_unref_page_prepare mm/page_alloc.c:3325 [inline]
 free_unref_page+0x19/0x690 mm/page_alloc.c:3404
 slab_destroy mm/slab.c:1630 [inline]
 slabs_destroy+0x89/0xc0 mm/slab.c:1650
 cache_flusharray mm/slab.c:3410 [inline]
 ___cache_free+0x303/0x600 mm/slab.c:3472
 qlink_free mm/kasan/quarantine.c:157 [inline]
 qlist_free_all+0x50/0x1a0 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x97/0xb0 mm/kasan/common.c:446
 kasan_slab_alloc include/linux/kasan.h:239 [inline]
 slab_post_alloc_hook mm/slab.h:732 [inline]
 slab_alloc_node mm/slab.c:3253 [inline]
 kmem_cache_alloc_node+0x2ea/0x590 mm/slab.c:3591
 __alloc_skb+0x215/0x340 net/core/skbuff.c:414
 alloc_skb include/linux/skbuff.h:1158 [inline]
 alloc_skb_with_frags+0x93/0x620 net/core/skbuff.c:5956
 sock_alloc_send_pskb+0x793/0x920 net/core/sock.c:2586
 unix_dgram_sendmsg+0x414/0x1a10 net/unix/af_unix.c:1896
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 sock_write_iter+0x289/0x3c0 net/socket.c:1061
 call_write_iter include/linux/fs.h:2074 [inline]
 new_sync_write+0x431/0x660 fs/read_write.c:503
 vfs_write+0x7cd/0xae0 fs/read_write.c:590

Memory state around the buggy address:
 ffff888077adc980: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff888077adca00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
>ffff888077adca80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                            ^
 ffff888077adcb00: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
 ffff888077adcb80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
==================================================================


---
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Re: [syzbot] KASAN: use-after-free Read in add_wait_queue

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    b47d5a4f6b8d Merge tag 'audit-pr-20220321' of git://git.ke..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=106365bd700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=63af44f0631a5c3a
dashboard link: https://syzkaller.appspot.com/bug?extid=950cee6d91e62329be2c
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14506ddb700000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=139b2093700000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+950cee6d91e62329be2c@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in __add_wait_queue include/linux/wait.h:177 [inline]
BUG: KASAN: use-after-free in add_wait_queue+0x1c0/0x260 kernel/sched/wait.c:24
Read of size 4 at addr ffff88807ec70f18 by task syz-executor133/3649

CPU: 1 PID: 3649 Comm: syz-executor133 Tainted: G        W         5.17.0-syzkaller-01442-gb47d5a4f6b8d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 print_address_description.constprop.0.cold+0x8d/0x336 mm/kasan/report.c:255
 __kasan_report mm/kasan/report.c:442 [inline]
 kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
 __add_wait_queue include/linux/wait.h:177 [inline]
 add_wait_queue+0x1c0/0x260 kernel/sched/wait.c:24
 __io_queue_proc+0x18c/0x6f0 fs/io_uring.c:6131
 poll_wait include/linux/poll.h:49 [inline]
 n_tty_poll+0x76/0x8a0 drivers/tty/n_tty.c:2322
 tty_poll+0x139/0x1b0 drivers/tty/tty_io.c:2212
 vfs_poll include/linux/poll.h:88 [inline]
 __io_arm_poll_handler+0x397/0xc00 fs/io_uring.c:6165
 io_arm_poll_handler+0x42c/0x940 fs/io_uring.c:6257
 io_queue_sqe_arm_apoll+0x6d/0x430 fs/io_uring.c:7499
 __io_queue_sqe fs/io_uring.c:7541 [inline]
 io_queue_sqe fs/io_uring.c:7568 [inline]
 io_submit_sqe fs/io_uring.c:7776 [inline]
 io_submit_sqes+0x7dda/0x9310 fs/io_uring.c:7882
 __do_sys_io_uring_enter+0x9f1/0x1520 fs/io_uring.c:10924
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f9692ff4fd9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 00 00 90 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffee24ecca8 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f9692ff4fd9
RDX: 0000000000000000 RSI: 0000000000001261 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000009668
R13: 00007ffee24ecccc R14: 00007ffee24ecce0 R15: 00007ffee24eccd0
 </TASK>

Allocated by task 3631:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:436 [inline]
 ____kasan_kmalloc mm/kasan/common.c:515 [inline]
 ____kasan_kmalloc mm/kasan/common.c:474 [inline]
 __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:524
 kmalloc include/linux/slab.h:581 [inline]
 io_arm_poll_handler+0x39d/0x940 fs/io_uring.c:6248
 io_queue_sqe_arm_apoll+0x6d/0x430 fs/io_uring.c:7499
 __io_queue_sqe fs/io_uring.c:7541 [inline]
 io_queue_sqe fs/io_uring.c:7568 [inline]
 io_submit_sqe fs/io_uring.c:7776 [inline]
 io_submit_sqes+0x7dda/0x9310 fs/io_uring.c:7882
 __do_sys_io_uring_enter+0x9f1/0x1520 fs/io_uring.c:10924
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 3615:
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track+0x21/0x30 mm/kasan/common.c:45
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370
 ____kasan_slab_free mm/kasan/common.c:366 [inline]
 ____kasan_slab_free+0x126/0x160 mm/kasan/common.c:328
 kasan_slab_free include/linux/kasan.h:215 [inline]
 slab_free_hook mm/slub.c:1728 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754
 slab_free mm/slub.c:3509 [inline]
 kfree+0xd0/0x390 mm/slub.c:4562
 io_flush_apoll_cache fs/io_uring.c:10038 [inline]
 io_ring_ctx_free fs/io_uring.c:10064 [inline]
 io_ring_exit_work+0x7f7/0x1053 fs/io_uring.c:10244
 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307
 worker_thread+0x657/0x1110 kernel/workqueue.c:2454
 kthread+0x2e9/0x3a0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

The buggy address belongs to the object at ffff88807ec70f00
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 24 bytes inside of
 96-byte region [ffff88807ec70f00, ffff88807ec70f60)
The buggy address belongs to the page:
page:ffffea0001fb1c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7ec70
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea00051d7980 dead000000000006 ffff888010c41780
raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY), pid 2955, ts 13260642360, free_ts 13233642928
 prep_new_page mm/page_alloc.c:2434 [inline]
 get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389
 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2271
 alloc_slab_page mm/slub.c:1799 [inline]
 allocate_slab+0x27f/0x3c0 mm/slub.c:1944
 new_slab mm/slub.c:2004 [inline]
 ___slab_alloc+0xbe1/0x12b0 mm/slub.c:3018
 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3105
 slab_alloc_node mm/slub.c:3196 [inline]
 slab_alloc mm/slub.c:3238 [inline]
 __kmalloc+0x372/0x450 mm/slub.c:4420
 kmalloc include/linux/slab.h:586 [inline]
 kzalloc include/linux/slab.h:714 [inline]
 tomoyo_commit_ok+0x1e/0x90 security/tomoyo/memory.c:76
 tomoyo_update_domain+0x5de/0x850 security/tomoyo/domain.c:139
 tomoyo_update_path_number_acl security/tomoyo/file.c:691 [inline]
 tomoyo_write_file+0x68b/0x7f0 security/tomoyo/file.c:1034
 tomoyo_write_domain2+0x116/0x1d0 security/tomoyo/common.c:1152
 tomoyo_add_entry security/tomoyo/common.c:2042 [inline]
 tomoyo_supervisor+0xbc7/0xf00 security/tomoyo/common.c:2103
 tomoyo_audit_path_number_log security/tomoyo/file.c:235 [inline]
 tomoyo_path_number_perm+0x419/0x590 security/tomoyo/file.c:734
 security_file_ioctl+0x50/0xb0 security/security.c:1557
 __do_sys_ioctl fs/ioctl.c:868 [inline]
 __se_sys_ioctl fs/ioctl.c:860 [inline]
 __x64_sys_ioctl+0xb3/0x200 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1352 [inline]
 free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1404
 free_unref_page_prepare mm/page_alloc.c:3325 [inline]
 free_unref_page_list+0x1a9/0xfa0 mm/page_alloc.c:3441
 release_pages+0x317/0x1220 mm/swap.c:980
 tlb_batch_pages_flush mm/mmu_gather.c:50 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:243 [inline]
 tlb_flush_mmu mm/mmu_gather.c:250 [inline]
 tlb_finish_mmu+0x165/0x8c0 mm/mmu_gather.c:341
 exit_mmap+0x21a/0x6a0 mm/mmap.c:3180
 __mmput+0x122/0x4b0 kernel/fork.c:1180
 mmput+0x56/0x60 kernel/fork.c:1202
 exit_mm kernel/exit.c:507 [inline]
 do_exit+0xa12/0x29d0 kernel/exit.c:793
 do_group_exit+0xd2/0x2f0 kernel/exit.c:936
 __do_sys_exit_group kernel/exit.c:947 [inline]
 __se_sys_exit_group kernel/exit.c:945 [inline]
 __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:945
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Memory state around the buggy address:
 ffff88807ec70e00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88807ec70e80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff88807ec70f00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                            ^
 ffff88807ec70f80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
 ffff88807ec71000: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
==================================================================

Re: [syzbot] KASAN: use-after-free Read in add_wait_queue

[Jens Axboe]

#syz test: git://git.kernel.dk/linux-block for-5.18/io_uring

-- 
Jens Axboe

Re: [syzbot] KASAN: use-after-free Read in add_wait_queue

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+950cee6d91e62329be2c@syzkaller.appspotmail.com

Tested on:

commit:         7d58de1a io_uring: don't recycle provided buffer if pu..
git tree:       git://git.kernel.dk/linux-block for-5.18/io_uring
kernel config:  https://syzkaller.appspot.com/x/.config?x=3172c0bf8614827
dashboard link: https://syzkaller.appspot.com/bug?extid=950cee6d91e62329be2c
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Note: no patches were applied.
Note: testing is done by a robot and is best-effort only.

Re: [syzbot] KASAN: use-after-free Read in add_wait_queue

[syzbot]

syzbot has bisected this issue to:

commit 91eac1c69c202d9dad8bf717ae5b92db70bfe5cf
Author: Jens Axboe <axboe@kernel.dk>
Date:   Wed Mar 16 22:59:10 2022 +0000

    io_uring: cache poll/double-poll state with a request flag

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1280c825700000
start commit:   b47d5a4f6b8d Merge tag 'audit-pr-20220321' of git://git.ke..
git tree:       upstream
final oops:     https://syzkaller.appspot.com/x/report.txt?x=1180c825700000
console output: https://syzkaller.appspot.com/x/log.txt?x=1680c825700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=63af44f0631a5c3a
dashboard link: https://syzkaller.appspot.com/bug?extid=950cee6d91e62329be2c
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14506ddb700000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=139b2093700000

Reported-by: syzbot+950cee6d91e62329be2c@syzkaller.appspotmail.com
Fixes: 91eac1c69c20 ("io_uring: cache poll/double-poll state with a request flag")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: [syzbot] KASAN: use-after-free Read in add_wait_queue

[Jens Axboe]

On 3/22/22 5:37 PM, syzbot wrote:
> syzbot has bisected this issue to:
> 
> commit 91eac1c69c202d9dad8bf717ae5b92db70bfe5cf
> Author: Jens Axboe <axboe@kernel.dk>
> Date:   Wed Mar 16 22:59:10 2022 +0000
> 
>     io_uring: cache poll/double-poll state with a request flag
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=1280c825700000
> start commit:   b47d5a4f6b8d Merge tag 'audit-pr-20220321' of git://git.ke..
> git tree:       upstream
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=1180c825700000
> console output: https://syzkaller.appspot.com/x/log.txt?x=1680c825700000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=63af44f0631a5c3a
> dashboard link: https://syzkaller.appspot.com/bug?extid=950cee6d91e62329be2c
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14506ddb700000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=139b2093700000
> 
> Reported-by: syzbot+950cee6d91e62329be2c@syzkaller.appspotmail.com
> Fixes: 91eac1c69c20 ("io_uring: cache poll/double-poll state with a request flag")
> 
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection

#syz test: git://git.kernel.dk/linux-block for-5.18/io_uring

All three reports are the same thing...

-- 
Jens Axboe

Re: [syzbot] KASAN: use-after-free Read in add_wait_queue

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+950cee6d91e62329be2c@syzkaller.appspotmail.com

Tested on:

commit:         7d58de1a io_uring: don't recycle provided buffer if pu..
git tree:       git://git.kernel.dk/linux-block for-5.18/io_uring
kernel config:  https://syzkaller.appspot.com/x/.config?x=3172c0bf8614827
dashboard link: https://syzkaller.appspot.com/bug?extid=950cee6d91e62329be2c
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

Note: no patches were applied.
Note: testing is done by a robot and is best-effort only.

Re: [syzbot] KASAN: use-after-free Read in add_wait_queue

[syzbot]

syzbot suspects this issue was fixed by commit:

commit d89a4fac0fbc6fe5fc24d1c9a889440dcf410368
Author: Jens Axboe <axboe@kernel.dk>
Date:   Tue Mar 22 19:11:28 2022 +0000

    io_uring: fix assuming triggered poll waitqueue is the single poll

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=17b70e42f00000
start commit:   b47d5a4f6b8d Merge tag 'audit-pr-20220321' of git://git.ke..
git tree:       upstream
kernel config:  https://syzkaller.appspot.com/x/.config?x=63af44f0631a5c3a
dashboard link: https://syzkaller.appspot.com/bug?extid=950cee6d91e62329be2c
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14506ddb700000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=139b2093700000

If the result looks correct, please mark the issue as fixed by replying with:

#syz fix: io_uring: fix assuming triggered poll waitqueue is the single poll

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: [syzbot] KASAN: use-after-free Read in add_wait_queue

[Jens Axboe]

#syz fix: io_uring: fix assuming triggered poll waitqueue is the single poll

-- 
Jens Axboe