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BUG: KMSAN: kernel-infoleak in kmsan_copy_to_user+0x9c/0xb0 mm/kmsan/kmsan_hooks.c:252
CPU: 1 PID: 11289 Comm: systemd-udevd Not tainted 5.13.0-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:121
 kmsan_internal_check_memory+0x1f5/0x500 mm/kmsan/kmsan.c:400
 kmsan_copy_to_user+0x9c/0xb0 mm/kmsan/kmsan_hooks.c:252
 instrument_copy_to_user include/linux/instrumented.h:126 [inline]
 copyout lib/iov_iter.c:189 [inline]
 copy_page_to_iter_iovec lib/iov_iter.c:264 [inline]
 copy_page_to_iter+0xaca/0x2240 lib/iov_iter.c:976
 filemap_read+0xe96/0x1aa0 mm/filemap.c:2605
 generic_file_read_iter+0x195/0xa50 mm/filemap.c:2701
 blkdev_read_iter+0x243/0x3b0 fs/block_dev.c:1730
 call_read_iter include/linux/fs.h:2108 [inline]
 new_sync_read fs/read_write.c:415 [inline]
 vfs_read+0x136b/0x15a0 fs/read_write.c:496
 ksys_read+0x275/0x500 fs/read_write.c:634
 __do_sys_read fs/read_write.c:644 [inline]
 __se_sys_read fs/read_write.c:642 [inline]
 __x64_sys_read+0xdb/0x120 fs/read_write.c:642
 do_syscall_64+0xb3/0x180 arch/x86/entry/common.c:53
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fa096055210
Code: 73 01 c3 48 8b 0d 98 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d b9 c1 20 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 4e fc ff ff 48 89 04 24
RSP: 002b:00007ffcba404bc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000055888cae6e50 RCX: 00007fa096055210
RDX: 0000000000000018 RSI: 000055888cae6e78 RDI: 000000000000000f
RBP: 000055888cae7e90 R08: 0000000000000000 R09: 0000000000000050
R10: 000055888cae6e68 R11: 0000000000000246 R12: 00000000001e0000
R13: 00000000001e0018 R14: 000055888cae7ee0 R15: 0000000000000018

Uninit was created at:
 kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:120
 kmsan_alloc_page+0xd0/0x1e0 mm/kmsan/kmsan_shadow.c:274
 __alloc_pages+0xb14/0xf70 mm/page_alloc.c:5241
 alloc_pages+0x7b6/0xb60 mm/mempolicy.c:2272
 __page_cache_alloc mm/filemap.c:1005 [inline]
 pagecache_get_page+0x111d/0x2040 mm/filemap.c:1885
 find_or_create_page include/linux/pagemap.h:420 [inline]
 grow_dev_page+0x1b8/0xe40 fs/buffer.c:974
 grow_buffers fs/buffer.c:1039 [inline]
 __getblk_slow fs/buffer.c:1066 [inline]
 __getblk_gfp+0x415/0x650 fs/buffer.c:1359
 sb_getblk_gfp include/linux/buffer_head.h:334 [inline]
 ext4_ext_split fs/ext4/extents.c:1077 [inline]
 ext4_ext_create_new_leaf fs/ext4/extents.c:1368 [inline]
 ext4_ext_insert_extent+0x3f7b/0x94f0 fs/ext4/extents.c:2054
 ext4_ext_map_blocks+0x5abe/0x76d0 fs/ext4/extents.c:4262
 ext4_map_blocks+0x172a/0x3820 fs/ext4/inode.c:638
 _ext4_get_block+0x2da/0xa30 fs/ext4/inode.c:794
 ext4_get_block_unwritten+0x9d/0xb0 fs/ext4/inode.c:825
 ext4_block_write_begin+0xb06/0x2440 fs/ext4/inode.c:1077
 ext4_write_begin+0xb9b/0x2d40 fs/ext4/ext4_jbd2.h:498
 ext4_da_write_begin+0x6ae/0x2080 fs/ext4/inode.c:2960
 generic_perform_write+0x459/0xb00 mm/filemap.c:3660
 ext4_buffered_write_iter+0x8b4/0xc40 fs/ext4/file.c:269
 ext4_file_write_iter+0x121e/0x36a0 fs/ext4/file.c:519
 call_write_iter include/linux/fs.h:2114 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x1083/0x1b00 fs/read_write.c:605
 ksys_write+0x275/0x500 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __ia32_sys_write+0xdb/0x120 fs/read_write.c:667
 do_syscall_32_irqs_on arch/x86/entry/common.c:84 [inline]
 __do_fast_syscall_32+0x132/0x1b0 arch/x86/entry/common.c:149
 do_fast_syscall_32+0x77/0xd0 arch/x86/entry/common.c:179
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:222
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

Bytes 8-11 of 24 are uninitialized
Memory access of size 24 starts at ffff8881236f7000
Data copied to user address 000055888cae6e78
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