From: syzbot <syzbot+aac438d7a1c44071e04b@syzkaller.appspotmail.com>
To: agruenba@redhat.com, gfs2@lists.linux.dev,
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: [syzbot] [gfs2?] memory leak in __kthread_create_on_node
Date: Fri, 30 Jan 2026 06:23:22 -0800 [thread overview]
Message-ID: <697cbeda.050a0220.142e72.0000.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 8dfce8991b95 Merge tag 'pinctrl-v6.19-3' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14361322580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9d7d0fbecb37bff8
dashboard link: https://syzkaller.appspot.com/bug?extid=aac438d7a1c44071e04b
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=1409c644580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16121694580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/5812cc8b60db/disk-8dfce899.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/47a4b40e4e44/vmlinux-8dfce899.xz
kernel image: https://storage.googleapis.com/syzbot-assets/18e043c20056/bzImage-8dfce899.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/ebd5c2300445/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=15765d8a580000)
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+aac438d7a1c44071e04b@syzkaller.appspotmail.com
BUG: memory leak
unreferenced object 0xffff888125a2dec0 (size 32):
comm "syz.4.75", pid 6411, jiffies 4294948981
hex dump (first 32 bytes):
67 66 73 32 5f 6c 6f 67 64 2f 73 79 7a 3a 73 79 gfs2_logd/syz:sy
7a 2e 30 00 00 00 00 00 00 00 00 00 00 00 00 00 z.0.............
backtrace (crc d543dd03):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4958 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
__do_kmalloc_node mm/slub.c:5656 [inline]
__kmalloc_node_track_caller_noprof+0x47b/0x690 mm/slub.c:5768
kvasprintf+0x6e/0xf0 lib/kasprintf.c:25
__kthread_create_on_node+0x9e/0x1c0 kernel/kthread.c:519
kthread_create_on_node+0x73/0xa0 kernel/kthread.c:587
init_threads fs/gfs2/ops_fstype.c:1065 [inline]
gfs2_fill_super+0xdf8/0x1210 fs/gfs2/ops_fstype.c:1265
get_tree_bdev_flags+0x1c0/0x290 fs/super.c:1691
gfs2_get_tree+0x26/0xd0 fs/gfs2/ops_fstype.c:1332
vfs_get_tree+0x30/0x120 fs/super.c:1751
fc_mount fs/namespace.c:1199 [inline]
do_new_mount_fc fs/namespace.c:3636 [inline]
do_new_mount fs/namespace.c:3712 [inline]
path_mount+0x5a9/0x1350 fs/namespace.c:4022
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount fs/namespace.c:4201 [inline]
__x64_sys_mount+0x1a3/0x1e0 fs/namespace.c:4201
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xa4/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
BUG: memory leak
unreferenced object 0xffff888126a2a300 (size 4480):
comm "kthreadd", pid 2, jiffies 4294948981
hex dump (first 32 bytes):
00 00 08 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 01 00 00 00 80 00 00 00 00 00 00 00 ................
backtrace (crc 4b33760e):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4958 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_node_noprof+0x422/0x590 mm/slub.c:5315
alloc_task_struct_node kernel/fork.c:184 [inline]
dup_task_struct kernel/fork.c:915 [inline]
copy_process+0x286/0x2870 kernel/fork.c:2052
kernel_clone+0xac/0x6e0 kernel/fork.c:2651
kernel_thread+0x80/0xb0 kernel/fork.c:2712
create_kthread kernel/kthread.c:486 [inline]
kthreadd+0x196/0x260 kernel/kthread.c:844
ret_from_fork+0x23c/0x320 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
BUG: memory leak
unreferenced object 0xffff888109c85180 (size 184):
comm "kthreadd", pid 2, jiffies 4294948981
hex dump (first 32 bytes):
02 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 c5f4f48b):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4958 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x412/0x580 mm/slub.c:5270
prepare_creds+0x22/0x600 kernel/cred.c:185
copy_creds+0x44/0x290 kernel/cred.c:286
copy_process+0x7a7/0x2870 kernel/fork.c:2086
kernel_clone+0xac/0x6e0 kernel/fork.c:2651
kernel_thread+0x80/0xb0 kernel/fork.c:2712
create_kthread kernel/kthread.c:486 [inline]
kthreadd+0x196/0x260 kernel/kthread.c:844
ret_from_fork+0x23c/0x320 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
BUG: memory leak
unreferenced object 0xffff888102bd9780 (size 32):
comm "kthreadd", pid 2, jiffies 4294948981
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
f8 52 86 00 81 88 ff ff 00 00 00 00 00 00 00 00 .R..............
backtrace (crc 336e1c5f):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4958 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
__do_kmalloc_node mm/slub.c:5656 [inline]
__kmalloc_noprof+0x465/0x680 mm/slub.c:5669
kmalloc_noprof include/linux/slab.h:961 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
lsm_blob_alloc+0x4d/0x80 security/security.c:192
lsm_cred_alloc security/security.c:209 [inline]
security_prepare_creds+0x2d/0x290 security/security.c:2763
prepare_creds+0x395/0x600 kernel/cred.c:215
copy_creds+0x44/0x290 kernel/cred.c:286
copy_process+0x7a7/0x2870 kernel/fork.c:2086
kernel_clone+0xac/0x6e0 kernel/fork.c:2651
kernel_thread+0x80/0xb0 kernel/fork.c:2712
create_kthread kernel/kthread.c:486 [inline]
kthreadd+0x196/0x260 kernel/kthread.c:844
ret_from_fork+0x23c/0x320 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
BUG: memory leak
unreferenced object 0xffff8881098abc00 (size 192):
comm "kthreadd", pid 2, jiffies 4294948981
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 ff ff ff ff ................
01 00 00 00 00 00 00 00 80 d5 78 82 ff ff ff ff ..........x.....
backtrace (crc 1df624ea):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4958 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
__kmalloc_cache_noprof+0x41a/0x590 mm/slub.c:5775
kmalloc_noprof include/linux/slab.h:957 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
set_kthread_struct+0x58/0x150 kernel/kthread.c:125
copy_process+0x1569/0x2870 kernel/fork.c:2150
kernel_clone+0xac/0x6e0 kernel/fork.c:2651
kernel_thread+0x80/0xb0 kernel/fork.c:2712
create_kthread kernel/kthread.c:486 [inline]
kthreadd+0x196/0x260 kernel/kthread.c:844
ret_from_fork+0x23c/0x320 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
BUG: memory leak
unreferenced object 0xffff88812baec5c0 (size 64):
comm "kthreadd", pid 2, jiffies 4294948981
hex dump (first 32 bytes):
e0 35 8f 89 ff ff ff ff 00 00 00 00 00 00 00 00 .5..............
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace (crc 8e7806b9):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4958 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
__do_kmalloc_node mm/slub.c:5656 [inline]
__kmalloc_noprof+0x465/0x680 mm/slub.c:5669
kmalloc_noprof include/linux/slab.h:961 [inline]
kzalloc_noprof include/linux/slab.h:1094 [inline]
lsm_blob_alloc+0x4d/0x80 security/security.c:192
lsm_task_alloc security/security.c:244 [inline]
security_task_alloc+0x2a/0x260 security/security.c:2682
copy_process+0xf07/0x2870 kernel/fork.c:2203
kernel_clone+0xac/0x6e0 kernel/fork.c:2651
kernel_thread+0x80/0xb0 kernel/fork.c:2712
create_kthread kernel/kthread.c:486 [inline]
kthreadd+0x196/0x260 kernel/kthread.c:844
ret_from_fork+0x23c/0x320 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
BUG: memory leak
unreferenced object 0xffff888101e37a80 (size 1152):
comm "kthreadd", pid 2, jiffies 4294948981
hex dump (first 32 bytes):
01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
90 7a e3 01 81 88 ff ff 90 7a e3 01 81 88 ff ff .z.......z......
backtrace (crc 1d024e88):
kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
slab_post_alloc_hook mm/slub.c:4958 [inline]
slab_alloc_node mm/slub.c:5263 [inline]
kmem_cache_alloc_noprof+0x412/0x580 mm/slub.c:5270
copy_signal kernel/fork.c:1699 [inline]
copy_process+0x1102/0x2870 kernel/fork.c:2218
kernel_clone+0xac/0x6e0 kernel/fork.c:2651
kernel_thread+0x80/0xb0 kernel/fork.c:2712
create_kthread kernel/kthread.c:486 [inline]
kthreadd+0x196/0x260 kernel/kthread.c:844
ret_from_fork+0x23c/0x320 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
connection error: failed to recv *flatrpc.ExecutorMessageRawT: EOF
---
This report is generated by a bot. It may contain errors.
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If the report is already addressed, let syzbot know by replying with:
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If you want syzbot to run the reproducer, reply with:
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If you want to overwrite report's subsystems, reply with:
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#syz undup
next reply other threads:[~2026-01-30 14:23 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-30 14:23 syzbot [this message]
2026-01-30 14:37 ` Forwarded: [PATCH] gfs2: fix memory leak of kernel threads on mount failure syzbot
2026-01-31 2:38 ` Forwarded: [PATCH] gfs2: fix memory leaks in gfs2_fill_super error path syzbot
2026-02-03 10:01 ` [syzbot] [gfs2?] memory leak in __kthread_create_on_node Andreas Gruenbacher
2026-02-03 13:35 ` syzbot
2026-02-04 11:39 ` Forwarded: " syzbot
2026-02-04 18:54 ` syzbot
[not found] <20260130143741.67498-1-kartikey406@gmail.com>
2026-01-30 15:20 ` syzbot
[not found] <20260131023756.72030-1-kartikey406@gmail.com>
2026-01-31 5:22 ` syzbot
[not found] <CAHc6FU5FACWy-y-t=qEyMsJHSv5D7A9XgYMdxbDh1S0tgz=kQg@mail.gmail.com>
2026-02-04 12:07 ` syzbot
[not found] <CAHc6FU6E=3FyN7WvSSydWfE2F_JXXWkfw6A9TD5PXatpp73SVQ@mail.gmail.com>
2026-02-04 19:15 ` syzbot
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