Dear Linux Developer, Recently when using our tool to fuzz kernel, the following crash was triggered:
HEAD commit: 64570fbc14f8 Linux 5.15-rc5 git tree: upstream compiler: gcc 8.0.1 console output: https://drive.google.com/file/d/1yppAEEN16x0lR3fd5t-NQ1itCoKLFtfP/view?usp=share_link kernel config: https://drive.google.com/file/d/1uDOeEYgJDcLiSOrx9W8v2bqZ6uOA_55t/view?usp=share_link Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: Wei Chen <[email protected]> RBP: 0000000020000000 R08: 00007f39b7fa3af0 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000100 R13: 00007f39b7fa3ab0 R14: 0000000000000001 R15: 0000000020047a20 gfs2: fsid=syz:syz.0: can't lookup journal index: 0 BUG: kernel NULL pointer dereference, address: 000000000000008c #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD c1e1067 P4D c1e1067 PUD 1a9e8067 PMD 0 Oops: 0000 [#1] PREEMPT SMP CPU: 0 PID: 11045 Comm: syz-executor.0 Not tainted 5.15.0-rc5 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-48-gd9c812dda519-prebuilt.qemu.org 04/01/2014 RIP: 0010:gfs2_evict_inode+0x47b/0xb00 Code: 3b 14 ff be 01 00 00 00 48 89 df e8 af 6f 44 ff 48 8b bb b8 04 00 00 31 f6 e8 e1 47 fd ff 49 8b 87 00 09 00 00 31 f6 4c 89 ff <8b> 90 8c 00 00 00 e8 ba 4a 00 00 31 ff 41 89 c5 89 c6 e8 ae 3c 14 RSP: 0018:ffffc9000df7fb10 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff888016648d10 RCX: 0000000000040000 RDX: ffffc900013d5000 RSI: 0000000000000000 RDI: ffff88801a800000 RBP: ffffc9000df7fbc0 R08: ffffffff8229378f R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000000 R12: ffff888016648f38 R13: 0000000000000000 R14: ffff88801a800000 R15: ffff88801a800000 FS: 00007f39b7fa4700(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000008c CR3: 0000000017567000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: evict+0x11c/0x230 iput+0x2e9/0x500 dentry_unlink_inode+0x111/0x1a0 __dentry_kill+0x186/0x280 dput.part.32+0x60d/0x940 gfs2_fill_super+0x8c1/0x10f0 get_tree_bdev+0x243/0x340 gfs2_get_tree+0x24/0xd0 vfs_get_tree+0x29/0x100 path_mount+0x58e/0x10a0 do_mount+0x9b/0xb0 __x64_sys_mount+0x13a/0x150 do_syscall_64+0x34/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x46abda Code: 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f39b7fa3a48 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f39b7fa3af0 RCX: 000000000046abda RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f39b7fa3ab0 RBP: 0000000020000000 R08: 00007f39b7fa3af0 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000100 R13: 00007f39b7fa3ab0 R14: 0000000000000001 R15: 0000000020047a20 Modules linked in: CR2: 000000000000008c ---[ end trace 194497c38992c5b1 ]--- RIP: 0010:gfs2_evict_inode+0x47b/0xb00 Code: 3b 14 ff be 01 00 00 00 48 89 df e8 af 6f 44 ff 48 8b bb b8 04 00 00 31 f6 e8 e1 47 fd ff 49 8b 87 00 09 00 00 31 f6 4c 89 ff <8b> 90 8c 00 00 00 e8 ba 4a 00 00 31 ff 41 89 c5 89 c6 e8 ae 3c 14 RSP: 0018:ffffc9000df7fb10 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff888016648d10 RCX: 0000000000040000 RDX: ffffc900013d5000 RSI: 0000000000000000 RDI: ffff88801a800000 RBP: ffffc9000df7fbc0 R08: ffffffff8229378f R09: 0000000000000000 R10: 0000000000000005 R11: 0000000000000000 R12: ffff888016648f38 R13: 0000000000000000 R14: ffff88801a800000 R15: ffff88801a800000 FS: 00007f39b7fa4700(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000000000008c CR3: 0000000017567000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 3b 14 ff cmp (%rdi,%rdi,8),%edx 3: be 01 00 00 00 mov $0x1,%esi 8: 48 89 df mov %rbx,%rdi b: e8 af 6f 44 ff callq 0xff446fbf 10: 48 8b bb b8 04 00 00 mov 0x4b8(%rbx),%rdi 17: 31 f6 xor %esi,%esi 19: e8 e1 47 fd ff callq 0xfffd47ff 1e: 49 8b 87 00 09 00 00 mov 0x900(%r15),%rax 25: 31 f6 xor %esi,%esi 27: 4c 89 ff mov %r15,%rdi * 2a: 8b 90 8c 00 00 00 mov 0x8c(%rax),%edx <-- trapping instruction 30: e8 ba 4a 00 00 callq 0x4aef 35: 31 ff xor %edi,%edi 37: 41 89 c5 mov %eax,%r13d 3a: 89 c6 mov %eax,%esi 3c: e8 .byte 0xe8 3d: ae scas %es:(%rdi),%al 3e: 3c 14 cmp $0x14,%al Best, Wei
