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KMSAN: uninit-value in iov_iter_advance

Status: auto-closed as invalid on 2019/08/06 08:57
Subsystems: fs
[Documentation on labels]
First crash: 1877d, last: 1877d

Sample crash report:
IPVS: ftp: loaded support on port[0] = 21
==================================================================
BUG: KMSAN: uninit-value in iov_iter_advance+0x1ee6/0x2020 lib/iov_iter.c:1035
CPU: 0 PID: 10313 Comm: syz-executor3 Not tainted 5.0.0-rc1+ #9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x173/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:600
 __msan_warning+0x82/0xf0 mm/kmsan/kmsan_instr.c:313
 iov_iter_advance+0x1ee6/0x2020 lib/iov_iter.c:1035
 do_loop_readv_writev fs/read_write.c:715 [inline]
 do_iter_read+0x990/0xe10 fs/read_write.c:921
 vfs_readv fs/read_write.c:983 [inline]
 do_readv+0x2a7/0x620 fs/read_write.c:1016
 __do_sys_readv fs/read_write.c:1103 [inline]
 __se_sys_readv+0x9b/0xb0 fs/read_write.c:1100
 __x64_sys_readv+0x4a/0x70 fs/read_write.c:1100
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x457e39
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f1933323c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000013
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e39
RDX: 0000000000000311 RSI: 00000000200003c0 RDI: 0000000000000003
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f19333246d4
R13: 00000000004c48fd R14: 00000000004d8360 R15: 00000000ffffffff

Uninit was created at:
 kmsan_save_stack_with_flags+0x7a/0x130 mm/kmsan/kmsan.c:205
 kmsan_internal_alloc_meta_for_pages+0x113/0x580 mm/kmsan/kmsan_hooks.c:98
 kmsan_alloc_page+0x7e/0x100 mm/kmsan/kmsan_hooks.c:396
 __alloc_pages_nodemask+0x137b/0x5e30 mm/page_alloc.c:4572
 alloc_pages_current+0x69d/0x9b0 mm/mempolicy.c:2106
 alloc_pages include/linux/gfp.h:511 [inline]
 kmalloc_order mm/slab_common.c:1229 [inline]
 kmalloc_order_trace+0xc1/0x3c0 mm/slab_common.c:1240
 kmalloc_large include/linux/slab.h:478 [inline]
 __kmalloc+0x308/0x3a0 mm/slub.c:3796
 kmalloc_array+0x6d/0xe0 include/linux/slab.h:668
 rw_copy_check_uvector+0x1ea/0x650 fs/read_write.c:778
 import_iovec+0x187/0x660 lib/iov_iter.c:1630
 vfs_readv fs/read_write.c:981 [inline]
 do_readv+0x22a/0x620 fs/read_write.c:1016
 __do_sys_readv fs/read_write.c:1103 [inline]
 __se_sys_readv+0x9b/0xb0 fs/read_write.c:1100
 __x64_sys_readv+0x4a/0x70 fs/read_write.c:1100
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/02/07 08:34 https://github.com/google/kmsan.git master fa1981bee40f d25487bc .config console log report ci-upstream-kmsan-gce
* Struck through repros no longer work on HEAD.