syzbot


BUG: unable to handle kernel NULL pointer dereference in __fget_files

Status: closed as invalid on 2020/06/17 13:13
Subsystems: fs
[Documentation on labels]
First crash: 1402d, last: 1402d

Sample crash report:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD a4961067 P4D a4961067 PUD 908ed067 PMD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 16150 Comm: syz-executor.0 Not tainted 5.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:252 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x3f/0x60 kernel/kcov.c:202
Code: c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 04 14 00 00 00 74 2c 8b 91 e0 13 00 00 83 fa 02 75 21 48 8b 91 e8 13 00 00 <48> 8b 32 48 8d 7e 01 8b 89 e4 13 00 00 48 39 cf 73 08 48 89 44 f2
RSP: 0018:ffffc90005bf77f0 EFLAGS: 00010246
RAX: ffffffff81c4ca4e RBX: ffffffff892e89d0 RCX: ffff888087c2a5c0
RDX: 0000000000000000 RSI: 000000000000baff RDI: 000000000000bb00
RBP: 0000000000000001 R08: dffffc0000000000 R09: ffffed1015d070fc
R10: ffffed1015d070fc R11: 0000000000000000 R12: 000000000000000a
R13: ffff8880a3067818 R14: ffff8880916caa00 R15: 0000000000000000
FS:  00007f5a8035c700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000a18e9000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rcu_lock_release+0xe/0x20 include/linux/rcupdate.h:246
 rcu_read_unlock include/linux/rcupdate.h:688 [inline]
 __fget_files+0x4b9/0x4e0 fs/file.c:734
 __fget fs/file.c:742 [inline]
 __fget_light fs/file.c:801 [inline]
 __fdget+0x18c/0x220 fs/file.c:809
 fdget include/linux/file.h:64 [inline]
 do_select+0xf86/0x19e0 fs/select.c:530
 core_sys_select+0x732/0x9e0 fs/select.c:677
 do_pselect fs/select.c:759 [inline]
 __do_sys_pselect6 fs/select.c:784 [inline]
 __se_sys_pselect6+0x35c/0x3f0 fs/select.c:769
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca59
Code: 0d b7 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5a8035bc78 EFLAGS: 00000246 ORIG_RAX: 000000000000010e
RAX: ffffffffffffffda RBX: 00000000004fb120 RCX: 000000000045ca59
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000040
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000140 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000087d R14: 00000000004cb686 R15: 00007f5a8035c6d4
Modules linked in:
CR2: 0000000000000000
---[ end trace d783d6b38677056b ]---
RIP: 0010:__read_once_size include/linux/compiler.h:252 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x3f/0x60 kernel/kcov.c:202
Code: c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 04 14 00 00 00 74 2c 8b 91 e0 13 00 00 83 fa 02 75 21 48 8b 91 e8 13 00 00 <48> 8b 32 48 8d 7e 01 8b 89 e4 13 00 00 48 39 cf 73 08 48 89 44 f2
RSP: 0018:ffffc90005bf77f0 EFLAGS: 00010246
RAX: ffffffff81c4ca4e RBX: ffffffff892e89d0 RCX: ffff888087c2a5c0
RDX: 0000000000000000 RSI: 000000000000baff RDI: 000000000000bb00
RBP: 0000000000000001 R08: dffffc0000000000 R09: ffffed1015d070fc
R10: ffffed1015d070fc R11: 0000000000000000 R12: 000000000000000a
R13: ffff8880a3067818 R14: ffff8880916caa00 R15: 0000000000000000
FS:  00007f5a8035c700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2c321000 CR3: 00000000a18e9000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/17 13:03 upstream 7ae77150d94d b9f3810b .config console log report ci-upstream-kasan-gce-smack-root
* Struck through repros no longer work on HEAD.