syzbot


WARNING in notify_change
Status: fixed on 2019/11/30 21:02
Reported-by: syzbot+aafdb1c16dd1a8e3048f@syzkaller.appspotmail.com
Fix commit: 2c5462425563 Abort file_remove_privs() for non-reg. files
First crash: 1138d, last: 1072d

Fix bisection: fixed by (bisect log) :
commit 2c54624255635a4f421fef9c7692f7fc9314b453
Author: Alexander Lochmann <alexander.lochmann@tu-dortmund.de>
Date: Fri Dec 14 10:55:52 2018 +0000

  Abort file_remove_privs() for non-reg. files

similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 WARNING in notify_change C done 12 1072d 1129d 1/1 fixed on 2019/12/01 09:13
upstream WARNING in notify_change C 566 1121d 1510d 13/22 fixed on 2019/07/24 12:46

Sample crash report:
random: sshd: uninitialized urandom read (32 bytes read)
audit: type=1400 audit(1556188307.054:36): avc:  denied  { map } for  pid=6979 comm="syz-executor711" path="/root/syz-executor711555728" dev="sda1" ino=16483 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1
------------[ cut here ]------------
WARNING: CPU: 1 PID: 6987 at fs/attr.c:213 notify_change+0xa32/0xd10 fs/attr.c:213
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 6987 Comm: syz-executor711 Not tainted 4.14.113 #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x138/0x19c lib/dump_stack.c:53
 panic+0x1f2/0x438 kernel/panic.c:182
 __warn.cold+0x2f/0x34 kernel/panic.c:546
 report_bug+0x216/0x254 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:177 [inline]
 fixup_bug arch/x86/kernel/traps.c:172 [inline]
 do_error_trap+0x1bb/0x310 arch/x86/kernel/traps.c:295
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
 invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:944
RIP: 0010:notify_change+0xa32/0xd10 fs/attr.c:213
RSP: 0018:ffff88809be2f5b0 EFLAGS: 00010297
RAX: ffff88807fed0200 RBX: ffff8880a489db60 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff88809be2f650 RDI: ffff8880a489dc40
RBP: ffff88809be2f600 R08: ffff88807fed0200 R09: 0000000000000000
R10: 0000000000000000 R11: ffff88807fed0200 R12: ffff88809be2f650
R13: 0000000000004200 R14: ffff8880a489db60 R15: ffff88809be2f6c0
 __remove_privs fs/inode.c:1806 [inline]
 file_remove_privs+0x229/0x430 fs/inode.c:1828
 __generic_file_write_iter+0x15e/0x5b0 mm/filemap.c:3095
 blkdev_write_iter fs/block_dev.c:1914 [inline]
 blkdev_write_iter+0x1e8/0x3a0 fs/block_dev.c:1891
 call_write_iter include/linux/fs.h:1774 [inline]
 do_iter_readv_writev+0x41e/0x680 fs/read_write.c:674
 do_iter_write fs/read_write.c:953 [inline]
 do_iter_write+0x154/0x550 fs/read_write.c:934
 vfs_iter_write+0x77/0xb0 fs/read_write.c:966
 iter_file_splice_write+0x578/0xae0 fs/splice.c:749
 do_splice_from fs/splice.c:851 [inline]
 direct_splice_actor+0x126/0x1a0 fs/splice.c:1018
 splice_direct_to_actor+0x2a1/0x7b0 fs/splice.c:973
 do_splice_direct+0x18d/0x230 fs/splice.c:1061
 do_sendfile+0x4db/0xbd0 fs/read_write.c:1440
 SYSC_sendfile64 fs/read_write.c:1501 [inline]
 SyS_sendfile64+0x102/0x110 fs/read_write.c:1487
 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x44a989
RSP: 002b:00007fa4968abce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00000000006dbc48 RCX: 000000000044a989
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000004
RBP: 00000000006dbc40 R08: 0000000000000000 R09: 0000000000000000
R10: 0020000102000007 R11: 0000000000000246 R12: 00000000006dbc4c
R13: 00007ffd18ea4a0f R14: 00007fa4968ac9c0 R15: 20c49ba5e353f7cf
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (14):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2019/04/25 10:36 linux-4.14.y 68d7a45eec10 8e3c52b1 .config log report syz C
ci2-linux-4-14 2019/06/21 08:44 linux-4.14.y bb263a2a2d43 34bf9440 .config log report
ci2-linux-4-14 2019/06/20 12:41 linux-4.14.y bb263a2a2d43 34bf9440 .config log report
ci2-linux-4-14 2019/06/20 04:41 linux-4.14.y bb263a2a2d43 34bf9440 .config log report
ci2-linux-4-14 2019/06/17 00:46 linux-4.14.y a74d0e937a3a 442206d7 .config log report
ci2-linux-4-14 2019/06/17 00:25 linux-4.14.y a74d0e937a3a 442206d7 .config log report
ci2-linux-4-14 2019/06/16 04:18 linux-4.14.y a74d0e937a3a 442206d7 .config log report
ci2-linux-4-14 2019/06/15 08:27 linux-4.14.y 2bf3258a12af 442206d7 .config log report
ci2-linux-4-14 2019/06/12 19:21 linux-4.14.y 2bf3258a12af 794a1ad7 .config log report
ci2-linux-4-14 2019/05/02 19:36 linux-4.14.y 1c046f373132 e9039493 .config log report
ci2-linux-4-14 2019/04/25 09:16 linux-4.14.y 68d7a45eec10 8e3c52b1 .config log report
ci2-linux-4-14 2019/04/23 22:46 linux-4.14.y 68d7a45eec10 2398edea .config log report
ci2-linux-4-14 2019/04/19 03:26 linux-4.14.y 58b454ebf81e b0e8efcb .config log report
ci2-linux-4-14 2019/04/16 15:38 linux-4.14.y 1ec8f1f0bffe 505ab413 .config log report