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BUG: unable to handle kernel NULL pointer dereference in __prepare_exit_to_usermode

Status: auto-closed as invalid on 2020/10/04 22:27
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+f3f2ecccf319cb82a652@syzkaller.appspotmail.com
First crash: 1393d, last: 1389d

Sample crash report:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0 
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 3880 Comm: systemd-udevd Not tainted 5.8.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:tracehook_notify_resume include/linux/tracehook.h:188 [inline]
RIP: 0010:exit_to_usermode_loop arch/x86/entry/common.c:216 [inline]
RIP: 0010:__prepare_exit_to_usermode+0x1e9/0x1f0 arch/x86/entry/common.c:246
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc90001077f18 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff8880a4d7e5c0 RCX: ffffffff814d2689
RDX: ffff8880a4d7e5c0 RSI: ffffffff81008049 RDI: 0000000000000005
RBP: 0000000000000102 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffc90001077f58
R13: ffff8880a4d7e5c0 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f3ef07c28c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000a3256000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 do_syscall_64+0x6c/0xe0 arch/x86/entry/common.c:368
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0 
Oops: 0002 [#2] PREEMPT SMP KASAN
CPU: 0 PID: 3880 Comm: systemd-udevd Not tainted 5.8.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:in_gate_area_no_mm+0x0/0x6a arch/x86/entry/vsyscall/vsyscall_64.c:343
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc90001077430 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffffc900010774d0 RCX: ffffffff816a5e30
RDX: ffff8880a4d7e5c0 RSI: ffffffff816a5e5b RDI: 00007f3eef5cba4b
RBP: 00007f3eef5cba4b R08: ffffc900010775e0 R09: ffffffff8c8cc109
R10: 00007f3eef5cba4b R11: 0000000000000000 R12: ffffc900010775e0
R13: 0000000000000001 R14: 00007f3eef5cba4b R15: ffffc900010774f0
FS:  00007f3ef07c28c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000a3256000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 is_kernel include/linux/kallsyms.h:43 [inline]
 is_ksym_addr include/linux/kallsyms.h:49 [inline]
 kallsyms_lookup+0xc3/0x2e0 kernel/kallsyms.c:290
 __sprint_symbol+0x9c/0x1c0 kernel/kallsyms.c:363
 symbol_string+0x14c/0x370 lib/vsprintf.c:969
 pointer+0x185/0x970 lib/vsprintf.c:2226
 vsnprintf+0x5b2/0x14f0 lib/vsprintf.c:2624
 vscnprintf+0x29/0x80 lib/vsprintf.c:2723
 vprintk_store+0x44/0x4a0 kernel/printk/printk.c:1942
 vprintk_emit+0x139/0x770 kernel/printk/printk.c:2003
 vprintk_func+0x8f/0x1a6 kernel/printk/printk_safe.c:393
 printk+0xba/0xed kernel/printk/printk.c:2070
 show_ip+0x22/0x30 arch/x86/kernel/dumpstack.c:124
 show_iret_regs+0x10/0x32 arch/x86/kernel/dumpstack.c:131
 __show_regs+0x18/0x50 arch/x86/kernel/process_64.c:72
 show_trace_log_lvl+0x255/0x2b4 arch/x86/kernel/dumpstack.c:274
 show_regs arch/x86/kernel/dumpstack.c:447 [inline]
 __die_body arch/x86/kernel/dumpstack.c:393 [inline]
 __die+0x51/0x90 arch/x86/kernel/dumpstack.c:407
 no_context+0x56b/0x9f0 arch/x86/mm/fault.c:695
 __bad_area_nosemaphore+0xa9/0x480 arch/x86/mm/fault.c:789
 do_user_addr_fault+0x8ce/0xd00 arch/x86/mm/fault.c:1258
 handle_page_fault arch/x86/mm/fault.c:1365 [inline]
 exc_page_fault+0xab/0x170 arch/x86/mm/fault.c:1418
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:565
RIP: 0010:tracehook_notify_resume include/linux/tracehook.h:188 [inline]
RIP: 0010:exit_to_usermode_loop arch/x86/entry/common.c:216 [inline]
RIP: 0010:__prepare_exit_to_usermode+0x1e9/0x1f0 arch/x86/entry/common.c:246
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc90001077f18 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff8880a4d7e5c0 RCX: ffffffff814d2689
RDX: ffff8880a4d7e5c0 RSI: ffffffff81008049 RDI: 0000000000000005
RBP: 0000000000000102 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffc90001077f58
R13: ffff8880a4d7e5c0 R14: 0000000000000000 R15: 0000000000000000
 do_syscall_64+0x6c/0xe0 arch/x86/entry/common.c:368
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 0 P4D 0 
Oops: 0002 [#3] PREEMPT SMP KASAN
CPU: 0 PID: 3880 Comm: systemd-udevd Not tainted 5.8.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:in_gate_area_no_mm+0x0/0x6a arch/x86/entry/vsyscall/vsyscall_64.c:343
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc90001076920 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffffc900010769c0 RCX: ffffffff816a5e30
RDX: ffff8880a4d7e5c0 RSI: ffffffff816a5e5b RDI: 00007f3eef5cba4b
RBP: 00007f3eef5cba4b R08: ffffc90001076ad0 R09: ffff8880ae623df8
R10: 00007f3eef5cba4b R11: 0000000000000001 R12: ffffc90001076ad0
R13: 0000000000000001 R14: 00007f3eef5cba4b R15: ffffc900010769e0
FS:  00007f3ef07c28c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000a3256000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 is_kernel include/linux/kallsyms.h:43 [inline]
 is_ksym_addr include/linux/kallsyms.h:49 [inline]
 kallsyms_lookup+0xc3/0x2e0 kernel/kallsyms.c:290
 __sprint_symbol+0x9c/0x1c0 kernel/kallsyms.c:363
 symbol_string+0x14c/0x370 lib/vsprintf.c:969
 pointer+0x185/0x970 lib/vsprintf.c:2226
 vsnprintf+0x5b2/0x14f0 lib/vsprintf.c:2624
 vscnprintf+0x29/0x80 lib/vsprintf.c:2723
 printk_safe_log_store+0xf5/0x250 kernel/printk/printk_safe.c:94
 vprintk_safe kernel/printk/printk_safe.c:347 [inline]
 vprintk_func+0xef/0x1a6 kernel/printk/printk_safe.c:390
 printk+0xba/0xed kernel/printk/printk.c:2070
 show_ip+0x22/0x30 arch/x86/kernel/dumpstack.c:124
 show_iret_regs+0x10/0x32 arch/x86/kernel/dumpstack.c:131
 __show_regs+0x18/0x50 arch/x86/kernel/process_64.c:72
 show_trace_log_lvl+0x255/0x2b4 arch/x86/kernel/dumpstack.c:274
 show_regs arch/x86/kernel/dumpstack.c:447 [inline]
 __die_body arch/x86/kernel/dumpstack.c:393 [inline]
 __die+0x51/0x90 arch/x86/kernel/dumpstack.c:407
 no_context+0x56b/0x9f0 arch/x86/mm/fault.c:695
 __bad_area_nosemaphore+0xa9/0x480 arch/x86/mm/fault.c:789
 do_user_addr_fault+0x783/0xd00 arch/x86/mm/fault.c:1171
 handle_page_fault arch/x86/mm/fault.c:1365 [inline]
 exc_page_fault+0xab/0x170 arch/x86/mm/fault.c:1418
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:565
RIP: 0010:in_gate_area_no_mm+0x0/0x6a arch/x86/entry/vsyscall/vsyscall_64.c:343
Code: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 <00> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 0018:ffffc90001077430 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffffc900010774d0 RCX: ffffffff816a5e30
RDX: ffff8880a4d7e5c0 RSI: ffffffff816a5e5b RDI: 00007f3eef5cba4b
RBP: 00007f3eef5cba4b R08: ffffc900010775e0 R09: ffffffff8c8cc109
R10: 00007f3eef5cba4b R11: 0000000000000000 R12: ffffc900010775e0
R13: 0000000000000001 R14: 00007f3eef5cba4b R15: ffffc900010774f0
 is_kernel include/linux/kallsyms.h:43 [inline]
 is_ksym_addr include/linux/kallsyms.h:49 [inline]
 kallsyms_lookup+0xc3/0x2e0 kernel/kallsyms.c:290
 __sprint_symbol+0x9c/0x1c0 kernel/kallsyms.c:363
 symbol_string+0x14c/0x370 lib/vsprintf.c:969
 pointer+0x185/0x970 lib/vsprintf.c:2226
 vsnprintf+0x5b2/0x14f0 lib/vsprintf.c:2624
 vscnprintf+0x29/0x80 lib/vsprintf.c:2723
 vprintk_store+0x44/0x4a0 kernel/printk/printk.c:1942
 vprintk_emit+0x139/0x770 kernel/printk/printk.c:2003
 vprintk_func+0x8f/0x1a6 kernel/printk/printk_safe.c:393
 printk+0xba/0xed kernel/printk/printk.c:2070
 show_ip+0x22/0x30 arch/x86/kernel/dumpstack.c:124
 show_iret_regs+0x10/0x32 arch/x86/kernel/dumpstack.c:131
 __show_regs+0x18/0x50 arch/x86/kernel/process_64.c:72
 show_trace_log_lvl+0x255/0x2b4 arch/x86/kernel/dumpstack.c:274
 show_regs arch/x86/kernel/dumpstack.c:447 [inline]
 __die_body arch/x86/kernel/dumpstack.c:393 [inline]
 __die+0x51/0x90 arch/x86/kernel/dumpstack.c:407
 no_context+0x56b/0x9f0 arch/x86/mm/fault.c:695
 __bad_area_nosemaphore+0xa9/0x480 arch/x86/mm/fault.c:789
 do_user_addr_fault+0x8ce/
Lost 47 message(s)!

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/07/03 02:06 upstream cd77006e01b3 bed10395 .config console log report ci-upstream-kasan-gce
2020/07/06 22:26 linux-next 9e50b94b3eb0 51095195 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.