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BUG: KMSAN: uninit-value in build_id_parse+0x3ff/0x17b0 lib/buildid.c:134
CPU: 0 PID: 10244 Comm: syz-executor.1 Tainted: G        W         5.12.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x24c/0x2e0 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5c/0xa0 mm/kmsan/kmsan_instr.c:197
 build_id_parse+0x3ff/0x17b0 lib/buildid.c:134
 perf_event_mmap_event kernel/events/core.c:8277 [inline]
 perf_event_mmap+0x2b35/0x2c20 kernel/events/core.c:8420
 mmap_region+0x200d/0x46c0 mm/mmap.c:1869
 do_mmap+0x1978/0x2650 mm/mmap.c:1581
 vm_mmap_pgoff+0x365/0x570 mm/util.c:519
 ksys_mmap_pgoff+0x59b/0xac0 mm/mmap.c:1632
 __do_sys_mmap_pgoff mm/mmap.c:1643 [inline]
 __se_sys_mmap_pgoff+0x11e/0x130 mm/mmap.c:1639
 __ia32_sys_mmap_pgoff+0x6e/0x90 mm/mmap.c:1639
 do_syscall_32_irqs_on arch/x86/entry/common.c:79 [inline]
 __do_fast_syscall_32+0x127/0x180 arch/x86/entry/common.c:142
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:167
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:210
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7f32549
Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f550b5fc EFLAGS: 00000296 ORIG_RAX: 00000000000000c0
RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 0000000000800000
RDX: 0000000000000009 RSI: 0000000000000052 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:121
 kmsan_alloc_page+0xd0/0x1e0 mm/kmsan/kmsan_shadow.c:274
 __alloc_pages_nodemask+0x827/0xf90 mm/page_alloc.c:5044
 alloc_pages_vma+0x139b/0x1ec0 mm/mempolicy.c:2240
 shmem_alloc_page+0x241/0x430 mm/shmem.c:1563
 shmem_alloc_and_acct_page+0x9b1/0x10c0 mm/shmem.c:1588
 shmem_getpage_gfp+0x1780/0x4b20 mm/shmem.c:1895
 shmem_getpage mm/shmem.c:155 [inline]
 shmem_fallocate+0x1087/0x1c10 mm/shmem.c:2787
 vfs_fallocate+0xd72/0x1550 fs/open.c:311
 __do_compat_sys_ioctl fs/ioctl.c:523 [inline]
 __se_compat_sys_ioctl+0xfec/0x1100 fs/ioctl.c:793
 __ia32_compat_sys_ioctl+0x4a/0x70 fs/ioctl.c:793
 do_syscall_32_irqs_on arch/x86/entry/common.c:79 [inline]
 __do_fast_syscall_32+0x127/0x180 arch/x86/entry/common.c:142
 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:167
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:210
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
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