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From: syzbot <syzbot+7666ed2c3d42196bf7e3@syzkaller.appspotmail.com>
To: brauner@kernel.org, jack@suse.cz, linux-fsdevel@vger.kernel.org,
	 linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com,
	 viro@zeniv.linux.org.uk
Subject: [syzbot] [fs?] memory leak in path_openat (4)
Date: Wed, 26 Aug 2026 07:54:38 -0700	[thread overview]
Message-ID: <6a8efe2e.1d9ded08.62e62.00b2.GAE@google.com> (raw)

Hello,

syzbot found the following issue on:

HEAD commit:    26260251022f Merge tag 'livepatching-for-7.3' of git://git..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1196a179580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6c1b5958b2d1207f
dashboard link: https://syzkaller.appspot.com/bug?extid=7666ed2c3d42196bf7e3
compiler:       gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=139f7179580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0f75e7622b1f/disk-26260251.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/2bbff9fd7b60/vmlinux-26260251.xz
kernel image: https://storage.googleapis.com/syzbot-assets/95d733004907/bzImage-26260251.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7666ed2c3d42196bf7e3@syzkaller.appspotmail.com

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


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup

             reply	other threads:[~2026-08-26 14:54 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-26 14:54 syzbot [this message]
2026-09-04  9:18 ` [syzbot] [fs?] memory leak in path_openat (4) Christian Brauner
2026-09-04  9:18   ` syzbot
2026-09-04  9:57     ` Aleksandr Nogikh
2026-09-04 11:47   ` Jason Gunthorpe

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