memory leak in path_openat (4)

Status: upstream: reported syz repro on 2026/08/26 14:54
Subsystems: fs
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+7666ed2c3d42196bf7e3@syzkaller.appspotmail.com
First crash: 4d12h, last: 4d12h
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ID Workflow Result Correct Bug Created Started Finished Revision
b206d047 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ memory leak in path_openat (4) 2026/08/22 14:48 2026/08/22 14:48 2026/08/22 15:21 1e72964b
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Title Replies (including bot) Last reply
[syzbot] [fs?] memory leak in path_openat (4) 0 (1) 2026/08/26 14:54
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream memory leak in path_openat (3) prio:high io-uring 3 syz, C 1 75d 75d 29/29 fixed on 2026/07/15 08:27
upstream memory leak in path_openat fs 3 syz, C 1 2432d 2428d 0/29 closed as invalid on 2020/03/07 22:28
upstream memory leak in path_openat (2) fs 3 syz, C 5 990d 2016d 0/29 auto-obsoleted due to no activity on 2025/08/18 09:36

Sample crash report:
2026/08/22 14:47:52 executed programs: 26
2026/08/22 14:47:59 executed programs: 40
2026/08/22 14:48:07 executed programs: 54
2026/08/22 14:48:14 executed programs: 68
BUG: memory leak
unreferenced object 0xffff88812811f9c0 (size 176):
  comm "syz.0.25", pid 6047, jiffies 4294943865
  hex dump (first 32 bytes):
    00 00 00 00 19 00 08 04 40 fc a8 85 ff ff ff ff  ........@.......
    00 02 38 03 81 88 ff ff 80 cd 61 11 81 88 ff ff  ..8.......a.....
  backtrace (crc 1214ee3a):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4599 [inline]
    slab_alloc_node mm/slub.c:4919 [inline]
    kmem_cache_alloc_noprof+0x352/0x440 mm/slub.c:4933
    alloc_empty_file+0x57/0x180 fs/file_table.c:262
    path_openat+0x44/0x11f0 fs/namei.c:4986
    do_file_open+0x121/0x200 fs/namei.c:5029
    do_sys_openat2+0xa7/0x150 fs/open.c:1417
    do_sys_open fs/open.c:1423 [inline]
    __do_sys_openat fs/open.c:1439 [inline]
    __se_sys_openat fs/open.c:1434 [inline]
    __x64_sys_openat+0x82/0xf0 fs/open.c:1434
    do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
    do_syscall_64+0xe9/0x530 arch/x86/entry/syscall_64.c:84
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff8881280ec188 (size 56):
  comm "syz.0.25", pid 6047, jiffies 4294943865
  hex dump (first 32 bytes):
    ff ff 01 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc 2672a0c6):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4599 [inline]
    slab_alloc_node mm/slub.c:4919 [inline]
    kmem_cache_alloc_noprof+0x352/0x440 mm/slub.c:4933
    lsm_file_alloc security/security.c:171 [inline]
    security_file_alloc+0x30/0x250 security/security.c:2406
    init_file+0x3e/0x160 fs/file_table.c:184
    alloc_empty_file+0x75/0x180 fs/file_table.c:266
    path_openat+0x44/0x11f0 fs/namei.c:4986
    do_file_open+0x121/0x200 fs/namei.c:5029
    do_sys_openat2+0xa7/0x150 fs/open.c:1417
    do_sys_open fs/open.c:1423 [inline]
    __do_sys_openat fs/open.c:1439 [inline]
    __se_sys_openat fs/open.c:1434 [inline]
    __x64_sys_openat+0x82/0xf0 fs/open.c:1434
    do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
    do_syscall_64+0xe9/0x530 arch/x86/entry/syscall_64.c:84
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff88811161cd80 (size 192):
  comm "syz.0.25", pid 6047, jiffies 4294943865
  hex dump (first 32 bytes):
    c0 f9 11 28 81 88 ff ff 00 00 00 00 2c 00 00 01  ...(........,...
    b2 6d b2 0e 81 88 ff ff 00 00 00 00 00 00 00 00  .m..............
  backtrace (crc 6cdefeb4):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4599 [inline]
    slab_alloc_node mm/slub.c:4919 [inline]
    __kmalloc_cache_noprof+0x359/0x440 mm/slub.c:5480
    _kmalloc_noprof include/linux/slab.h:988 [inline]
    _kzalloc_noprof include/linux/slab.h:1309 [inline]
    iommufd_fops_open+0x24/0xe0 drivers/iommu/iommufd/main.c:319
    misc_open+0x12a/0x1f0 drivers/char/misc.c:163
    chrdev_open+0x108/0x310 fs/char_dev.c:411
    do_dentry_open+0x1fc/0x850 fs/open.c:996
    vfs_open+0x3d/0x1b0 fs/open.c:1101
    do_open fs/namei.c:4837 [inline]
    path_openat+0xde7/0x11f0 fs/namei.c:5000
    do_file_open+0x121/0x200 fs/namei.c:5029
    do_sys_openat2+0xa7/0x150 fs/open.c:1417
    do_sys_open fs/open.c:1423 [inline]
    __do_sys_openat fs/open.c:1439 [inline]
    __se_sys_openat fs/open.c:1434 [inline]
    __x64_sys_openat+0x82/0xf0 fs/open.c:1434
    do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
    do_syscall_64+0xe9/0x530 arch/x86/entry/syscall_64.c:84
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff888127dd4000 (size 256):
  comm "syz.0.25", pid 6047, jiffies 4294943865
  hex dump (first 32 bytes):
    01 00 00 00 01 00 00 00 04 00 00 00 01 00 00 00  ................
    00 00 00 00 00 00 00 00 01 48 cf 0a 81 88 ff ff  .........H......
  backtrace (crc 98731819):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4599 [inline]
    slab_alloc_node mm/slub.c:4919 [inline]
    __do_kmalloc_node mm/slub.c:5336 [inline]
    __kmalloc_noprof+0x3c2/0x560 mm/slub.c:5362
    _kmalloc_noprof include/linux/slab.h:992 [inline]
    _kzalloc_noprof include/linux/slab.h:1309 [inline]
    _iommufd_object_alloc+0x24/0x100 drivers/iommu/iommufd/main.c:41
    iommufd_ioas_alloc drivers/iommu/iommufd/ioas.c:28 [inline]
    iommufd_ioas_alloc_ioctl+0x46/0x160 drivers/iommu/iommufd/ioas.c:47
    iommufd_fops_ioctl+0x1ed/0x370 drivers/iommu/iommufd/main.c:556
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:597 [inline]
    __se_sys_ioctl fs/ioctl.c:583 [inline]
    __x64_sys_ioctl+0xf4/0x140 fs/ioctl.c:583
    do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
    do_syscall_64+0xe9/0x530 arch/x86/entry/syscall_64.c:84
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff88810eb26db0 (size 576):
  comm "syz.0.25", pid 6047, jiffies 4294943865
  hex dump (first 32 bytes):
    00 17 02 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    88 cd 61 11 81 88 ff ff c8 6d b2 0e 81 88 ff ff  ..a......m......
  backtrace (crc f41786a5):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4599 [inline]
    slab_alloc_node mm/slub.c:4919 [inline]
    kmem_cache_alloc_lru_noprof+0x350/0x440 mm/slub.c:4952
    xas_alloc+0xf1/0x110 lib/xarray.c:378
    xas_expand lib/xarray.c:590 [inline]
    xas_create+0x105/0x8a0 lib/xarray.c:661
    xas_store+0x7a/0xb20 lib/xarray.c:795
    __xa_alloc+0xec/0x200 lib/xarray.c:2005
    xa_alloc include/linux/xarray.h:878 [inline]
    _iommufd_object_alloc+0x9d/0x100 drivers/iommu/iommufd/main.c:56
    iommufd_ioas_alloc drivers/iommu/iommufd/ioas.c:28 [inline]
    iommufd_ioas_alloc_ioctl+0x46/0x160 drivers/iommu/iommufd/ioas.c:47
    iommufd_fops_ioctl+0x1ed/0x370 drivers/iommu/iommufd/main.c:556
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:597 [inline]
    __se_sys_ioctl fs/ioctl.c:583 [inline]
    __x64_sys_ioctl+0xf4/0x140 fs/ioctl.c:583
    do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
    do_syscall_64+0xe9/0x530 arch/x86/entry/syscall_64.c:84
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

BUG: memory leak
unreferenced object 0xffff88811161ccc0 (size 192):
  comm "syz.0.25", pid 6047, jiffies 4294943865
  hex dump (first 32 bytes):
    01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc 21b0f99b):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4599 [inline]
    slab_alloc_node mm/slub.c:4919 [inline]
    __kmalloc_cache_noprof+0x359/0x440 mm/slub.c:5480
    _kmalloc_noprof include/linux/slab.h:988 [inline]
    _kzalloc_noprof include/linux/slab.h:1309 [inline]
    iopt_alloc_pages.part.0+0x2b/0x210 drivers/iommu/iommufd/pages.c:1375
    iopt_alloc_pages drivers/iommu/iommufd/pages.c:1432 [inline]
    iopt_alloc_file_pages+0x7c/0xf0 drivers/iommu/iommufd/pages.c:1425
    iopt_map_file_pages+0x184/0x1e0 drivers/iommu/iommufd/io_pagetable.c:518
    iommufd_ioas_map_file+0x152/0x2f0 drivers/iommu/iommufd/ioas.c:231
    iommufd_fops_ioctl+0x1ed/0x370 drivers/iommu/iommufd/main.c:556
    vfs_ioctl fs/ioctl.c:51 [inline]
    __do_sys_ioctl fs/ioctl.c:597 [inline]
    __se_sys_ioctl fs/ioctl.c:583 [inline]
    __x64_sys_ioctl+0xf4/0x140 fs/ioctl.c:583
    do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
    do_syscall_64+0xe9/0x530 arch/x86/entry/syscall_64.c:84
    entry_SYSCALL_64_after_hwframe+0x77/0x7f

connection error: failed to recv *flatrpc.ExecutorMessageRawT: read tcp 127.0.0.1:41845->127.0.0.1:36772: read: connection reset by peer

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/22 14:48 upstream 26260251022f 1e72964b .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-gce-leak memory leak in path_openat
* Struck through repros no longer work on HEAD.