bisecting fixing commit since 10b84daddbec72c6b440216a69de9a9605127f7a building syzkaller on 0174c6c8f78a3fdd002a73a5fdf559c1b0ec8c34 testing commit 10b84daddbec72c6b440216a69de9a9605127f7a with gcc (GCC) 8.1.0 all runs: crashed: general protection fault in hfs_find_init testing current HEAD 1e78030e5e5b2d8b0cad7136caf9cfab986a6bff testing commit 1e78030e5e5b2d8b0cad7136caf9cfab986a6bff with gcc (GCC) 8.1.0 all runs: crashed: general protection fault in hfs_find_init revisions tested: 2, total time: 18m0.260334423s (build: 9m56.794435809s, test: 6m38.142308431s) the crash still happens on HEAD crash: general protection fault in hfs_find_init IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 IPVS: ftp: loaded support on port[0] = 21 kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] SMP KASAN CPU: 1 PID: 4406 Comm: syz-executor Not tainted 5.3.0-rc2+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:hfs_find_init+0x73/0x180 fs/hfs/bfind.c:21 Code: ea 03 80 3c 02 00 0f 85 ee 00 00 00 4d 8d 6c 24 40 48 c7 43 18 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e ac 00 00 00 41 8b 44 24 40 be RSP: 0018:ffff8881cdf0f300 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8881cdf0f380 RCX: 1ffff1103b285465 RDX: 0000000000000008 RSI: ffff8881cdf0f380 RDI: ffff8881cdf0f398 RBP: ffff8881cdf0f320 R08: 0000000000000000 R09: ffff8881cdf0f3e0 R10: 0000000000000000 R11: ffff8881d21996cf R12: 0000000000000000 R13: 0000000000000040 R14: ffff8881d2199772 R15: ffff8881cdf0f380 FS: 00007f348c6fb700(0000) GS:ffff8881db100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f598bb07518 CR3: 00000001d0043000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: hfs_ext_read_extent+0x17e/0xcc0 fs/hfs/extent.c:200 hfs_get_block+0x490/0x850 fs/hfs/extent.c:366 block_read_full_page+0x288/0x940 fs/buffer.c:2245 hfs_readpage+0x13/0x20 fs/hfs/inode.c:38 do_read_cache_page+0x65c/0x12d0 mm/filemap.c:2829 read_cache_page+0x45/0x70 mm/filemap.c:2920 read_mapping_page include/linux/pagemap.h:386 [inline] hfs_btree_open+0x45f/0x1070 fs/hfs/btree.c:78 hfs_mdb_get+0x1329/0x1d85 fs/hfs/mdb.c:193 hfs_fill_super+0x9b4/0x12a0 fs/hfs/super.c:407 mount_bdev+0x27b/0x340 fs/super.c:1283 hfs_mount+0x10/0x20 fs/hfs/super.c:457 legacy_get_tree+0x103/0x1f0 fs/fs_context.c:661 vfs_get_tree+0x8b/0x360 fs/super.c:1413 do_new_mount fs/namespace.c:2791 [inline] do_mount+0x584/0x1b40 fs/namespace.c:3111 ksys_mount+0xba/0xe0 fs/namespace.c:3320 __do_sys_mount fs/namespace.c:3334 [inline] __se_sys_mount fs/namespace.c:3331 [inline] __x64_sys_mount+0xb9/0x150 fs/namespace.c:3331 do_syscall_64+0xd6/0x550 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x4579fa Code: b8 a6 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 dd 8f fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 ba 8f fb ff c3 66 0f 1f 84 00 00 00 00 00 RSP: 002b:00007f348c6fabb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 00000000004579fa RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f348c6fac00 RBP: 0000000000000003 R08: 00000000200001c0 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000666 R14: 00000000006fba30 R15: 0000000000000000 Modules linked in: ---[ end trace 1250045075753ef5 ]--- hfs: unable to locate alternate MDB RIP: 0010:hfs_find_init+0x73/0x180 fs/hfs/bfind.c:21 hfs: continuing without an alternate MDB kasan: CONFIG_KASAN_INLINE enabled Code: ea 03 80 3c 02 00 0f 85 ee 00 00 00 4d 8d 6c 24 40 48 c7 43 18 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e ac 00 00 00 41 8b 44 24 40 be RSP: 0018:ffff8881cdf0f300 EFLAGS: 00010202 kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#2] SMP KASAN CPU: 0 PID: 4425 Comm: syz-executor1 Tainted: G D 5.3.0-rc2+ #1 RAX: dffffc0000000000 RBX: ffff8881cdf0f380 RCX: 1ffff1103b285465 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:hfs_find_init+0x73/0x180 fs/hfs/bfind.c:21 Code: ea 03 80 3c 02 00 0f 85 ee 00 00 00 4d 8d 6c 24 40 48 c7 43 18 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <0f> b6 04 02 84 c0 74 08 3c 03 0f 8e ac 00 00 00 41 8b 44 24 40 be RSP: 0018:ffff8881d939f300 EFLAGS: 00010202 RAX: dffffc0000000000 RBX: ffff8881d939f380 RCX: 1ffff110399b78f5 RDX: 0000000000000008 RSI: ffff8881d939f380 RDI: ffff8881d939f398 RBP: ffff8881d939f320 R08: ffffed103b26f6e2 R09: ffff8881d939f3e0 R10: 0000000000000000 R11: ffff8881d937b70f R12: 0000000000000000 RDX: 0000000000000008 RSI: ffff8881cdf0f380 RDI: ffff8881cdf0f398 R13: 0000000000000040 R14: ffff8881d937b7b2 R15: ffff8881d939f380 FS: 00007f3d4acde700(0000) GS:ffff8881db000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f598c151000 CR3: 00000001bc918000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: hfs_ext_read_extent+0x17e/0xcc0 fs/hfs/extent.c:200 RBP: ffff8881cdf0f320 R08: 0000000000000000 R09: ffff8881cdf0f3e0 hfs_get_block+0x490/0x850 fs/hfs/extent.c:366 block_read_full_page+0x288/0x940 fs/buffer.c:2245 R10: 0000000000000000 R11: ffff8881d21996cf R12: 0000000000000000 hfs_readpage+0x13/0x20 fs/hfs/inode.c:38 do_read_cache_page+0x65c/0x12d0 mm/filemap.c:2829 R13: 0000000000000040 R14: ffff8881d2199772 R15: ffff8881cdf0f380 FS: 00007f348c6fb700(0000) GS:ffff8881db100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 read_cache_page+0x45/0x70 mm/filemap.c:2920 read_mapping_page include/linux/pagemap.h:386 [inline] hfs_btree_open+0x45f/0x1070 fs/hfs/btree.c:78 hfs_mdb_get+0x1329/0x1d85 fs/hfs/mdb.c:193 CR2: 00007f598bb07518 CR3: 00000001d0043000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 hfs_fill_super+0x9b4/0x12a0 fs/hfs/super.c:407 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400