syzbot


KMSAN: uninit-value in hrtimer_wakeup

Status: upstream: reported on 2025/07/24 10:44
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+e84a763987edd173d82f@syzkaller.appspotmail.com
First crash: 38d, last: 38d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kernel?] KMSAN: uninit-value in hrtimer_wakeup 1 (2) 2025/07/24 15:31

Sample crash report:
=====================================================
BUG: KMSAN: uninit-value in hrtimer_wakeup+0xcb/0xd0 kernel/time/hrtimer.c:1997
 hrtimer_wakeup+0xcb/0xd0 kernel/time/hrtimer.c:1997
 __run_hrtimer kernel/time/hrtimer.c:1761 [inline]
 __hrtimer_run_queues+0x556/0xd80 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x456/0xb80 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
 __sysvec_apic_timer_interrupt+0xa7/0x420 arch/x86/kernel/apic/apic.c:1056
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0x7f/0x90 arch/x86/kernel/apic/apic.c:1050
 asm_sysvec_apic_timer_interrupt+0x1f/0x30 arch/x86/include/asm/idtentry.h:702
 memmove+0x28/0x1b0 arch/x86/lib/memmove_64.S:45
 ext4_xattr_set_entry+0x1928/0x3440 fs/ext4/xattr.c:1773
 ext4_xattr_block_set+0xc82/0x5010 fs/ext4/xattr.c:2020
 ext4_xattr_set_handle+0x2a44/0x2c00 fs/ext4/xattr.c:2447
 ext4_xattr_set+0x2ff/0x5b0 fs/ext4/xattr.c:2549
 ext4_xattr_trusted_set+0x51/0x70 fs/ext4/xattr_trusted.c:38
 __vfs_setxattr+0x742/0x850 fs/xattr.c:200
 __vfs_setxattr_noperm+0x224/0xad0 fs/xattr.c:234
 __vfs_setxattr_locked+0x448/0x490 fs/xattr.c:295
 vfs_setxattr+0x27f/0x640 fs/xattr.c:321
 do_setxattr fs/xattr.c:636 [inline]
 filename_setxattr+0x3a4/0xcc0 fs/xattr.c:665
 path_setxattrat+0x734/0x820 fs/xattr.c:713
 __do_sys_lsetxattr fs/xattr.c:754 [inline]
 __se_sys_lsetxattr fs/xattr.c:750 [inline]
 __x64_sys_lsetxattr+0x103/0x1c0 fs/xattr.c:750
 x64_sys_call+0x2464/0x3db0 arch/x86/include/generated/asm/syscalls_64.h:190
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd9/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Local variable t created at:
 hrtimer_nanosleep+0x48/0x480 kernel/time/hrtimer.c:2142
 common_nsleep+0x118/0x160 kernel/time/posix-timers.c:1353

CPU: 0 UID: 0 PID: 17784 Comm: syz.6.3366 Not tainted 6.16.0-rc6-syzkaller-00279-gbf61759db409 #0 PREEMPT(none) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
=====================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/20 10:39 upstream bf61759db409 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: uninit-value in hrtimer_wakeup
* Struck through repros no longer work on HEAD.