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BUG: KMSAN: uninit-value in build_id_parse+0x3ff/0x17b0 lib/buildid.c:134
CPU: 1 PID: 15436 Comm: syz-executor.2 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: 0023:0xf7f65549
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:00000000f553e5fc EFLAGS: 00000296 ORIG_RAX: 00000000000000c0
RAX: ffffffffffffffda RBX: 0000000020ffa000 RCX: 0000000000003000
RDX: 000000000000000a RSI: 0000000000000012 RDI: 0000000000000004
RBP: 000000009bfb4000 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_current+0x7b6/0xb60 mm/mempolicy.c:2277
 alloc_pages include/linux/gfp.h:561 [inline]
 __page_cache_alloc+0xbd/0x290 mm/filemap.c:978
 page_cache_ra_unbounded+0x519/0xf40 mm/readahead.c:216
 ondemand_readahead+0x1390/0x1dc0 mm/readahead.c:267
 page_cache_sync_ra+0x4f8/0x510 mm/readahead.c:577
 page_cache_sync_readahead include/linux/pagemap.h:840 [inline]
 filemap_get_pages+0x51c/0x14c0 mm/filemap.c:2375
 filemap_read+0x5ff/0x1aa0 mm/filemap.c:2458
 generic_file_read_iter+0x1bb/0xd40 mm/filemap.c:2609
 blkdev_read_iter+0x220/0x2f0 fs/block_dev.c:1727
 call_read_iter include/linux/fs.h:1971 [inline]
 generic_file_splice_read+0x74b/0xb70 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x757/0x14c0 fs/splice.c:870
 do_splice_direct+0x3a1/0x5f0 fs/splice.c:979
 do_sendfile+0x1ae9/0x2ae0 fs/read_write.c:1260
 __do_compat_sys_sendfile fs/read_write.c:1346 [inline]
 __se_compat_sys_sendfile+0x373/0x440 fs/read_write.c:1329
 __ia32_compat_sys_sendfile+0x56/0x70 fs/read_write.c:1329
 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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