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memory leak in io_submit_sqes (5)

Status: upstream: reported syz repro on 2025/12/01 17:07
Subsystems: io-uring
[Documentation on labels]
Reported-by: syzbot+641eec6b7af1f62f2b99@syzkaller.appspotmail.com
Fix commit: io_uring/poll: correctly handle io_poll_add() return value on update
Patched on: [ci-upstream-linux-next-kasan-gce-root ci-upstream-rust-kasan-gce], missing on: [ci-qemu-gce-upstream-auto ci-qemu-native-arm64-kvm ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb]
First crash: 4d01h, last: 3d23h
▶ ▼ Discussions (2)
Title Replies (including bot) Last reply
[syzbot] [io-uring?] memory leak in io_submit_sqes (5) 4 (8) 2025/12/01 21:52
[PATCH] io_uring/poll: correctly handle io_poll_add() return value on update 1 (1) 2025/12/01 21:06
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream memory leak in io_submit_sqes fs io-uring 3 C 2 1923d 1942d 15/29 fixed on 2020/09/16 22:51
upstream memory leak in io_submit_sqes (2) fs io-uring 3 C 1 1738d 1738d 20/29 fixed on 2021/04/09 19:46
upstream memory leak in io_submit_sqes (4) io-uring 3 C 1 1062d 1061d 22/29 fixed on 2023/06/08 14:41
upstream memory leak in io_submit_sqes (3) fs io-uring 3 C 1 1652d 1651d 0/29 auto-obsoleted due to no activity on 2022/10/10 15:32
▶ ▼ Last patch testing requests (3)
Created Duration User Patch Repo Result
2025/12/01 21:31 19m axboe@kernel.dk patch upstream OK log
2025/12/01 20:36 23m ssranevjti@gmail.com patch upstream report log
2025/12/01 20:16 41m axboe@kernel.dk patch git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git v6.18 error

Sample crash report:
2025/12/01 19:06:02 executed programs: 5
BUG: memory leak
unreferenced object 0xffff88812612b200 (size 248):
  comm "syz.0.17", pid 6080, jiffies 4294945075
  hex dump (first 32 bytes):
    40 12 ef 0c 81 88 ff ff 00 00 00 00 00 00 00 00  @...............
    3c 20 00 c0 00 00 00 00 00 00 00 00 00 00 00 00  < ..............
  backtrace (crc af24a25):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4983 [inline]
    kmem_cache_alloc_bulk_noprof+0x220/0x3e0 mm/slub.c:7497
    __io_alloc_req_refill+0x54/0x1a0 io_uring/io_uring.c:1058
    io_alloc_req io_uring/io_uring.h:543 [inline]
    io_submit_sqes+0x584/0xe80 io_uring/io_uring.c:2438
    __do_sys_io_uring_enter+0x83f/0xcf0 io_uring/io_uring.c:3516
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff88812615b200 (size 248):
  comm "syz.0.18", pid 6082, jiffies 4294945076
  hex dump (first 32 bytes):
    40 12 ef 0c 81 88 ff ff 00 00 00 00 00 00 00 00  @...............
    3c 20 00 c0 00 00 00 00 00 00 00 00 00 00 00 00  < ..............
  backtrace (crc 4d803735):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4983 [inline]
    kmem_cache_alloc_bulk_noprof+0x220/0x3e0 mm/slub.c:7497
    __io_alloc_req_refill+0x54/0x1a0 io_uring/io_uring.c:1058
    io_alloc_req io_uring/io_uring.h:543 [inline]
    io_submit_sqes+0x584/0xe80 io_uring/io_uring.c:2438
    __do_sys_io_uring_enter+0x83f/0xcf0 io_uring/io_uring.c:3516
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff888111143d00 (size 248):
  comm "syz.0.19", pid 6085, jiffies 4294945078
  hex dump (first 32 bytes):
    40 12 ef 0c 81 88 ff ff 00 00 00 00 00 00 00 00  @...............
    3c 20 00 c0 00 00 00 00 00 00 00 00 00 00 00 00  < ..............
  backtrace (crc 3cb6e82d):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4983 [inline]
    kmem_cache_alloc_bulk_noprof+0x220/0x3e0 mm/slub.c:7497
    __io_alloc_req_refill+0x54/0x1a0 io_uring/io_uring.c:1058
    io_alloc_req io_uring/io_uring.h:543 [inline]
    io_submit_sqes+0x584/0xe80 io_uring/io_uring.c:2438
    __do_sys_io_uring_enter+0x83f/0xcf0 io_uring/io_uring.c:3516
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff88810d84a400 (size 248):
  comm "syz.0.20", pid 6126, jiffies 4294945722
  hex dump (first 32 bytes):
    40 12 ef 0c 81 88 ff ff 00 00 00 00 00 00 00 00  @...............
    3c 20 00 c0 00 00 00 00 00 00 00 00 00 00 00 00  < ..............
  backtrace (crc 9def3f66):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4983 [inline]
    kmem_cache_alloc_bulk_noprof+0x220/0x3e0 mm/slub.c:7497
    __io_alloc_req_refill+0x54/0x1a0 io_uring/io_uring.c:1058
    io_alloc_req io_uring/io_uring.h:543 [inline]
    io_submit_sqes+0x584/0xe80 io_uring/io_uring.c:2438
    __do_sys_io_uring_enter+0x83f/0xcf0 io_uring/io_uring.c:3516
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff88810995e500 (size 248):
  comm "syz.0.21", pid 6127, jiffies 4294945723
  hex dump (first 32 bytes):
    40 12 ef 0c 81 88 ff ff 00 00 00 00 00 00 00 00  @...............
    3c 20 00 c0 00 00 00 00 00 00 00 00 00 00 00 00  < ..............
  backtrace (crc a8791491):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4983 [inline]
    kmem_cache_alloc_bulk_noprof+0x220/0x3e0 mm/slub.c:7497
    __io_alloc_req_refill+0x54/0x1a0 io_uring/io_uring.c:1058
    io_alloc_req io_uring/io_uring.h:543 [inline]
    io_submit_sqes+0x584/0xe80 io_uring/io_uring.c:2438
    __do_sys_io_uring_enter+0x83f/0xcf0 io_uring/io_uring.c:3516
    do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
    do_syscall_64+0xa4/0xfa0 arch/x86/entry/syscall_64.c:94
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/01 19:06 upstream 7d0a66e4bb90 d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in io_submit_sqes
2025/12/01 17:57 upstream 7d0a66e4bb90 d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in io_submit_sqes
2025/12/01 16:45 upstream 7d0a66e4bb90 d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in io_submit_sqes
* Struck through repros no longer work on HEAD.