Extracting prog: 1m7.354074854s
Minimizing prog: 2m32.257947276s
Simplifying prog options: 0s
Extracting C: 27.025223329s
Simplifying C: 4m55.869014546s


extracting reproducer from 1 programs
testing a last program of every proc
single: executing 1 programs separately with timeout 30s
testing program (duration=30s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_mount_image$erofs-open
detailed listing:
executing program 0:
syz_mount_image$erofs(&(0x7f0000000040), &(0x7f0000000100)='./bus\x00', 0x210c11, &(0x7f00000001c0)=ANY=[@ANYRES64=0x0, @ANYRES8, @ANYRESHEX=0x0, @ANYRESHEX, @ANYRES32], 0x2, 0x231, &(0x7f0000000440)="$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")
open(&(0x7f0000000000)='./cgroup.cpu/cpuset.cpus\x00', 0x1a1342, 0x0)

program crashed: BUG: unable to handle kernel NULL pointer dereference in z_erofs_decompress
single: successfully extracted reproducer
found reproducer with 2 syscalls
minimizing guilty program
testing program (duration=36.697548097s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_mount_image$erofs
detailed listing:
executing program 0:
syz_mount_image$erofs(&(0x7f0000000040), &(0x7f0000000100)='./bus\x00', 0x210c11, &(0x7f00000001c0)=ANY=[@ANYRES64=0x0, @ANYRES8, @ANYRESHEX=0x0, @ANYRESHEX, @ANYRES32], 0x2, 0x231, &(0x7f0000000440)="$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")

program did not crash
testing program (duration=36.697548097s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): open
detailed listing:
executing program 0:
open(&(0x7f0000000000)='./cgroup.cpu/cpuset.cpus\x00', 0x1a1342, 0x0)

program did not crash
testing program (duration=36.697548097s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_mount_image$erofs-open
detailed listing:
executing program 0:
syz_mount_image$erofs(&(0x7f0000000040), &(0x7f0000000100)='./bus\x00', 0x210c11, &(0x7f00000001c0)=ANY=[@ANYRES64=0x0, @ANYRES8, @ANYRESHEX=0x0, @ANYRESHEX, @ANYRES32], 0x2, 0x231, &(0x7f0000000440)="$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")
open(0x0, 0x1a1342, 0x0)

program did not crash
extracting C reproducer
testing compiled C program (duration=36.697548097s, {Threaded:true Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_mount_image$erofs-open
program crashed: BUG: unable to handle kernel NULL pointer dereference in z_erofs_decompress
simplifying C reproducer
testing compiled C program (duration=36.697548097s, {Threaded:false Repeat:true RepeatTimes:0 Procs:5 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:true Cgroups:true BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_mount_image$erofs-open
program crashed: BUG: unable to handle kernel NULL pointer dereference in z_erofs_decompress
testing compiled C program (duration=36.697548097s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox:none SandboxArg:0 Leak:false NetInjection:true NetDevices:true NetReset:false Cgroups:false BinfmtMisc:true CloseFDs:true KCSAN:false DevlinkPCI:false NicVF:false USB:true VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:true UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_mount_image$erofs-open
program crashed: BUG: unable to handle kernel NULL pointer dereference in z_erofs_decompress
testing compiled C program (duration=36.697548097s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:true HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_mount_image$erofs-open
program crashed: BUG: unable to handle kernel NULL pointer dereference in z_erofs_decompress
testing compiled C program (duration=36.697548097s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:true Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_mount_image$erofs-open
program crashed: BUG: unable to handle kernel NULL pointer dereference in z_erofs_decompress
testing compiled C program (duration=36.697548097s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:true Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_mount_image$erofs-open
program crashed: BUG: unable to handle kernel NULL pointer dereference in z_erofs_decompress
testing compiled C program (duration=36.697548097s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_mount_image$erofs-open
program crashed: BUG: unable to handle kernel NULL pointer dereference in z_erofs_decompress
testing program (duration=36.697548097s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_mount_image$erofs-open
detailed listing:
executing program 0:
syz_mount_image$erofs(&(0x7f0000000040), &(0x7f0000000100)='./bus\x00', 0x210c11, &(0x7f00000001c0)=ANY=[@ANYRES64=0x0, @ANYRES8, @ANYRESHEX=0x0, @ANYRESHEX, @ANYRES32], 0x2, 0x231, &(0x7f0000000440)="$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")
open(&(0x7f0000000000)='./cgroup.cpu/cpuset.cpus\x00', 0x1a1342, 0x0)

program crashed: BUG: unable to handle kernel NULL pointer dereference in z_erofs_decompress
validation run: crashed=true
testing program (duration=36.697548097s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_mount_image$erofs-open
detailed listing:
executing program 0:
syz_mount_image$erofs(&(0x7f0000000040), &(0x7f0000000100)='./bus\x00', 0x210c11, &(0x7f00000001c0)=ANY=[@ANYRES64=0x0, @ANYRES8, @ANYRESHEX=0x0, @ANYRESHEX, @ANYRES32], 0x2, 0x231, &(0x7f0000000440)="$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")
open(&(0x7f0000000000)='./cgroup.cpu/cpuset.cpus\x00', 0x1a1342, 0x0)

program crashed: BUG: unable to handle kernel NULL pointer dereference in z_erofs_decompress
validation run: crashed=true
testing program (duration=36.697548097s, {Threaded:false Repeat:false RepeatTimes:0 Procs:1 Slowdown:1 Sandbox: SandboxArg:0 Leak:false NetInjection:false NetDevices:false NetReset:false Cgroups:false BinfmtMisc:false CloseFDs:false KCSAN:false DevlinkPCI:false NicVF:false USB:false VhciInjection:false Wifi:false IEEE802154:false Sysctl:false Swap:false UseTmpDir:false HandleSegv:false Trace:false CallComments:true LegacyOptions:{Collide:false Fault:false FaultCall:0 FaultNth:0}}): syz_mount_image$erofs-open
detailed listing:
executing program 0:
syz_mount_image$erofs(&(0x7f0000000040), &(0x7f0000000100)='./bus\x00', 0x210c11, &(0x7f00000001c0)=ANY=[@ANYRES64=0x0, @ANYRES8, @ANYRESHEX=0x0, @ANYRESHEX, @ANYRES32], 0x2, 0x231, &(0x7f0000000440)="$eJzsmc9rE0EUx78z2Wy29Rce9OAlHgpWsJvdjUovIvXiqSK0Ih6DXUvbaSNJkCYgtH+Af4Dg3+GhJw/evHnw5EEFoQdz9CBCR3Z3JjvZ7TZuA158H+j0u29m3sx7O3kDCQiC+G/59vXnl1f3FldvADiLOdSU/bCiR1jgxvjPrytVJd/vnH95kPXHAEiZPlsT1rcBvFuqAHuJWynT2b8kMBf7ZFgFj3XEI3BcV/oxGFy9V5nODsHwRJk3Dd2eUUKE7GlbrD3bEKEXNX7UBFHTBOTY/of7DGsAHLUEM/bf7Q+2dH62WkKEncjSEqIq9TraUiSc4q5EYLM4f/H+ljjuGCngwAXd76r/npE/Hxy+0k0wrCi9iBpc162rx9A34r9ipf4ryWsbxX9CbBnhDM6peWVmnVpcXJjWz92SAR4rjmSuaw/TB2if6hWUFdHHb/LgaB/ll+D1/Cx7kh9n6tSxrIWZB/Ly8OBDftb3Mcun5aIlGP7FwS4n4sIFINf1cVaI5dSi61qn27805udqkp8H2cNmH1f4zCOBw/tqyDWjPlnGrdDobT9vdPuDhY3t1nq4Hu4EQfO2d9PzbgWNqK56jbhCn1D/nLg+zRr+qwVjbWZjt9XrdfxdoNfxR89B0hoVd+Vt+8eozA/3OeZ/S6mvlzhsdVGyzBpM/fE3yb0FzFcKN08QBEEQBEEQBEEQBEEQBPGX1IAzQB0M6rvKI/1rlcxhBQ/xYgb4EwAA//+UxFZA")
open(&(0x7f0000000000)='./cgroup.cpu/cpuset.cpus\x00', 0x1a1342, 0x0)

program crashed: BUG: unable to handle kernel NULL pointer dereference in z_erofs_decompress
validation run: crashed=true
reproducing took 11m30.063953966s
repro crashed as (corrupted=false):
loop2: detected capacity change from 0 to 16
erofs: (device loop2): mounted with root inode @ nid 36.
erofs: (device loop2): z_erofs_extent_lookback: bogus lookback distance @ nid 36
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 123e22067 P4D 123e22067 PUD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 373 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc9000400eb48 EFLAGS: 00010246
RAX: 1ffffffff0ac1962 RBX: ffffc9000400f4a0 RCX: ffff88811172e2c0
RDX: 0000000000000000 RSI: ffffc9000400f4a0 RDI: ffffc9000400f000
RBP: ffffc9000400eb70 R08: ffffc9000400f02f R09: ffffc9000400f02a
R10: dffffc0000000000 R11: fffff52000801e06 R12: dffffc0000000000
R13: 000000000000073b R14: ffffc9000400f000 R15: ffffffff8560cb10
FS:  000055557dfaa500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000012ee91000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 z_erofs_decompress+0x79/0xb0 fs/erofs/decompressor.c:360
 z_erofs_decompress_pcluster fs/erofs/zdata.c:1110 [inline]
 z_erofs_decompress_queue+0x10d4/0x1a30 fs/erofs/zdata.c:1188
 z_erofs_runqueue+0x113e/0x11c0 fs/erofs/zdata.c:-1
 z_erofs_readpage+0x25d/0x4d0 fs/erofs/zdata.c:1601
 do_read_cache_page+0x66e/0xa30 mm/filemap.c:-1
 read_cache_page+0x50/0x70 mm/filemap.c:3659
 read_mapping_page include/linux/pagemap.h:513 [inline]
 find_target_block_classic fs/erofs/namei.c:104 [inline]
 erofs_namei+0x152/0xfa0 fs/erofs/namei.c:184
 erofs_lookup+0xa5/0x260 fs/erofs/namei.c:228
 __lookup_slow+0x2b8/0x410 fs/namei.c:1671
 lookup_slow+0x57/0x70 fs/namei.c:1688
 walk_component+0x325/0x460 fs/namei.c:1984
 link_path_walk+0x665/0xd60 fs/namei.c:-1
 path_openat+0x27b/0x2f20 fs/namei.c:3746
 do_filp_open+0x1e2/0x410 fs/namei.c:3777
 do_sys_openat2+0x15e/0x7f0 fs/open.c:1236
 do_sys_open fs/open.c:1252 [inline]
 __do_sys_open fs/open.c:1260 [inline]
 __se_sys_open fs/open.c:1256 [inline]
 __x64_sys_open+0x11c/0x140 fs/open.c:1256
 x64_sys_call+0x3fc/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:3
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fb5425e5dd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffce6f6e8f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fb54285efa0 RCX: 00007fb5425e5dd9
RDX: 0000000000000000 RSI: 00000000001a1342 RDI: 0000200000000000
RBP: 00007fb54267bd69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb54285efac R14: 00007fb54285efa0 R15: 00007fb54285efa0
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 1ba30838848932bb ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc9000400eb48 EFLAGS: 00010246
RAX: 1ffffffff0ac1962 RBX: ffffc9000400f4a0 RCX: ffff88811172e2c0
RDX: 0000000000000000 RSI: ffffc9000400f4a0 RDI: ffffc9000400f000
RBP: ffffc9000400eb70 R08: ffffc9000400f02f R09: ffffc9000400f02a
R10: dffffc0000000000 R11: fffff52000801e06 R12: dffffc0000000000
R13: 000000000000073b R14: ffffc9000400f000 R15: ffffffff8560cb10
FS:  000055557dfaa500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000012ee91000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

final repro crashed as (corrupted=false):
loop2: detected capacity change from 0 to 16
erofs: (device loop2): mounted with root inode @ nid 36.
erofs: (device loop2): z_erofs_extent_lookback: bogus lookback distance @ nid 36
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 123e22067 P4D 123e22067 PUD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 373 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc9000400eb48 EFLAGS: 00010246
RAX: 1ffffffff0ac1962 RBX: ffffc9000400f4a0 RCX: ffff88811172e2c0
RDX: 0000000000000000 RSI: ffffc9000400f4a0 RDI: ffffc9000400f000
RBP: ffffc9000400eb70 R08: ffffc9000400f02f R09: ffffc9000400f02a
R10: dffffc0000000000 R11: fffff52000801e06 R12: dffffc0000000000
R13: 000000000000073b R14: ffffc9000400f000 R15: ffffffff8560cb10
FS:  000055557dfaa500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000012ee91000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 z_erofs_decompress+0x79/0xb0 fs/erofs/decompressor.c:360
 z_erofs_decompress_pcluster fs/erofs/zdata.c:1110 [inline]
 z_erofs_decompress_queue+0x10d4/0x1a30 fs/erofs/zdata.c:1188
 z_erofs_runqueue+0x113e/0x11c0 fs/erofs/zdata.c:-1
 z_erofs_readpage+0x25d/0x4d0 fs/erofs/zdata.c:1601
 do_read_cache_page+0x66e/0xa30 mm/filemap.c:-1
 read_cache_page+0x50/0x70 mm/filemap.c:3659
 read_mapping_page include/linux/pagemap.h:513 [inline]
 find_target_block_classic fs/erofs/namei.c:104 [inline]
 erofs_namei+0x152/0xfa0 fs/erofs/namei.c:184
 erofs_lookup+0xa5/0x260 fs/erofs/namei.c:228
 __lookup_slow+0x2b8/0x410 fs/namei.c:1671
 lookup_slow+0x57/0x70 fs/namei.c:1688
 walk_component+0x325/0x460 fs/namei.c:1984
 link_path_walk+0x665/0xd60 fs/namei.c:-1
 path_openat+0x27b/0x2f20 fs/namei.c:3746
 do_filp_open+0x1e2/0x410 fs/namei.c:3777
 do_sys_openat2+0x15e/0x7f0 fs/open.c:1236
 do_sys_open fs/open.c:1252 [inline]
 __do_sys_open fs/open.c:1260 [inline]
 __se_sys_open fs/open.c:1256 [inline]
 __x64_sys_open+0x11c/0x140 fs/open.c:1256
 x64_sys_call+0x3fc/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:3
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fb5425e5dd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffce6f6e8f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007fb54285efa0 RCX: 00007fb5425e5dd9
RDX: 0000000000000000 RSI: 00000000001a1342 RDI: 0000200000000000
RBP: 00007fb54267bd69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb54285efac R14: 00007fb54285efa0 R15: 00007fb54285efa0
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 1ba30838848932bb ]---
RIP: 0010:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 0018:ffffc9000400eb48 EFLAGS: 00010246
RAX: 1ffffffff0ac1962 RBX: ffffc9000400f4a0 RCX: ffff88811172e2c0
RDX: 0000000000000000 RSI: ffffc9000400f4a0 RDI: ffffc9000400f000
RBP: ffffc9000400eb70 R08: ffffc9000400f02f R09: ffffc9000400f02a
R10: dffffc0000000000 R11: fffff52000801e06 R12: dffffc0000000000
R13: 000000000000073b R14: ffffc9000400f000 R15: ffffffff8560cb10
FS:  000055557dfaa500(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 000000012ee91000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400