[syzbot] [kernel?] memory leak in do_timer_create

[syzbot <syzbot+9c47ad18f978d4394986@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    24172e0d7990 Merge tag 'arm64-fixes' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=165417cd980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=cb128cd5cb439809
dashboard link: https://syzkaller.appspot.com/bug?extid=9c47ad18f978d4394986
compiler:       gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15004914580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16ea6b42580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ded911fa4408/disk-24172e0d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a1f3e61cb784/vmlinux-24172e0d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b92fd0e25cb7/bzImage-24172e0d.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9c47ad18f978d4394986@syzkaller.appspotmail.com

2025/11/12 09:47:51 executed programs: 5
BUG: memory leak
unreferenced object 0xffff888108465800 (size 384):
  comm "syz.0.17", pid 6100, jiffies 4294944668
  hex dump (first 32 bytes):
    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 00  ................
  backtrace (crc 1025e73e):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4983 [inline]
    slab_alloc_node mm/slub.c:5288 [inline]
    kmem_cache_alloc_noprof+0x397/0x5a0 mm/slub.c:5295
    alloc_posix_timer kernel/time/posix-timers.c:429 [inline]
    do_timer_create+0xe0/0x800 kernel/time/posix-timers.c:478
    __do_sys_timer_create kernel/time/posix-timers.c:584 [inline]
    __se_sys_timer_create kernel/time/posix-timers.c:573 [inline]
    __x64_sys_timer_create+0xdb/0xf0 kernel/time/posix-timers.c:573
    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 0xffff8881084a0000 (size 384):
  comm "syz.0.18", pid 6104, jiffies 4294944670
  hex dump (first 32 bytes):
    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 00  ................
  backtrace (crc 63c47fd0):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4983 [inline]
    slab_alloc_node mm/slub.c:5288 [inline]
    kmem_cache_alloc_noprof+0x397/0x5a0 mm/slub.c:5295
    alloc_posix_timer kernel/time/posix-timers.c:429 [inline]
    do_timer_create+0xe0/0x800 kernel/time/posix-timers.c:478
    __do_sys_timer_create kernel/time/posix-timers.c:584 [inline]
    __se_sys_timer_create kernel/time/posix-timers.c:573 [inline]
    __x64_sys_timer_create+0xdb/0xf0 kernel/time/posix-timers.c:573
    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 0xffff8881084a0180 (size 384):
  comm "syz.0.19", pid 6107, jiffies 4294944671
  hex dump (first 32 bytes):
    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 00  ................
  backtrace (crc d769495f):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4983 [inline]
    slab_alloc_node mm/slub.c:5288 [inline]
    kmem_cache_alloc_noprof+0x397/0x5a0 mm/slub.c:5295
    alloc_posix_timer kernel/time/posix-timers.c:429 [inline]
    do_timer_create+0xe0/0x800 kernel/time/posix-timers.c:478
    __do_sys_timer_create kernel/time/posix-timers.c:584 [inline]
    __se_sys_timer_create kernel/time/posix-timers.c:573 [inline]
    __x64_sys_timer_create+0xdb/0xf0 kernel/time/posix-timers.c:573
    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 0xffff888108464600 (size 384):
  comm "syz.0.20", pid 6127, jiffies 4294945201
  hex dump (first 32 bytes):
    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 00  ................
  backtrace (crc a3c907e):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4983 [inline]
    slab_alloc_node mm/slub.c:5288 [inline]
    kmem_cache_alloc_noprof+0x397/0x5a0 mm/slub.c:5295
    alloc_posix_timer kernel/time/posix-timers.c:429 [inline]
    do_timer_create+0xe0/0x800 kernel/time/posix-timers.c:478
    __do_sys_timer_create kernel/time/posix-timers.c:584 [inline]
    __se_sys_timer_create kernel/time/posix-timers.c:573 [inline]
    __x64_sys_timer_create+0xdb/0xf0 kernel/time/posix-timers.c:573
    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 0xffff8881084a0300 (size 384):
  comm "syz.0.21", pid 6128, jiffies 4294945201
  hex dump (first 32 bytes):
    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 00  ................
  backtrace (crc bb0da4da):
    kmemleak_alloc_recursive include/linux/kmemleak.h:44 [inline]
    slab_post_alloc_hook mm/slub.c:4983 [inline]
    slab_alloc_node mm/slub.c:5288 [inline]
    kmem_cache_alloc_noprof+0x397/0x5a0 mm/slub.c:5295
    alloc_posix_timer kernel/time/posix-timers.c:429 [inline]
    do_timer_create+0xe0/0x800 kernel/time/posix-timers.c:478
    __do_sys_timer_create kernel/time/posix-timers.c:584 [inline]
    __se_sys_timer_create kernel/time/posix-timers.c:573 [inline]
    __x64_sys_timer_create+0xdb/0xf0 kernel/time/posix-timers.c:573
    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


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