bisecting fixing commit since d18b78abc0c6e7d3119367c931c583e02d466495
building syzkaller on 67b599d167ab42fff545ec53e23f2711c184877b
testing commit d18b78abc0c6e7d3119367c931c583e02d466495 with gcc (GCC) 8.1.0
kernel signature: 5a6b230914af88435cce426a47e4dff0bacaf5a022bbaea592699438a1cd1719
run #0: crashed: general protection fault in security_inode_getattr
run #1: crashed: general protection fault in security_inode_getattr
run #2: OK
run #3: crashed: general protection fault in security_inode_getattr
run #4: crashed: general protection fault in security_inode_getattr
run #5: crashed: general protection fault in security_inode_getattr
run #6: OK
run #7: OK
run #8: OK
run #9: OK
testing current HEAD f5d8eef067acee3fda37137f4a08c0d3f6427a8e
testing commit f5d8eef067acee3fda37137f4a08c0d3f6427a8e with gcc (GCC) 8.1.0
kernel signature: dc100fd9e49029f18907eaae090ca9371e2cdf85468d8128780f36a675d310e3
run #0: crashed: general protection fault in security_inode_getattr
run #1: crashed: general protection fault in security_inode_getattr
run #2: crashed: general protection fault in security_inode_getattr
run #3: crashed: general protection fault in security_inode_getattr
run #4: crashed: general protection fault in security_inode_getattr
run #5: OK
run #6: OK
run #7: crashed: general protection fault in security_inode_getattr
run #8: OK
run #9: OK
revisions tested: 2, total time: 39m18.394851417s (build: 17m19.637712366s, test: 21m16.793815517s)
the crash still happens on HEAD
commit msg: Linux 4.19.154
crash: general protection fault in security_inode_getattr
Process accounting resumed
Process accounting resumed
Process accounting resumed
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 27520 Comm: syz-executor395 Not tainted 4.19.154-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:d_backing_inode include/linux/dcache.h:543 [inline]
RIP: 0010:security_inode_getattr+0x44/0x100 security/security.c:722
Code: 41 54 48 c1 ea 03 53 80 3c 02 00 0f 85 ca 00 00 00 48 b8 00 00 00 00 00 fc ff df 49 8b 5d 08 48 8d 7b 58 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 9d 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b
RSP: 0018:ffff8880b0197590 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000000b RSI: ffff8880b0197790 RDI: 0000000000000058
RBP: ffff8880b01975a8 R08: 0000000000000000 R09: ffffed10174e473a
R10: ffffed10174e473a R11: ffff8880ba7239d3 R12: ffff8880b0197790
R13: ffff8880b0197780 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007f7f63225700(0000) GS:ffff8880ba700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7f63245e78 CR3: 00000000aca32000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 vfs_getattr+0x1c/0x40 fs/stat.c:113
 ovl_copy_up_one+0x136/0xb30 fs/overlayfs/copy_up.c:775
 ovl_copy_up_flags+0x104/0x160 fs/overlayfs/copy_up.c:856
 ovl_maybe_copy_up+0xcb/0x100 fs/overlayfs/copy_up.c:888
 ovl_open+0x9c/0x230 fs/overlayfs/file.c:126
 do_dentry_open+0x3f1/0x1010 fs/open.c:796
 vfs_open+0x9a/0xc0 fs/open.c:902
 do_last fs/namei.c:3421 [inline]
 path_openat+0x905/0x2870 fs/namei.c:3537
 do_filp_open+0x177/0x250 fs/namei.c:3567