syzbot


ASan: Unauthorized Access in ufs_rmdir

Status: upstream: reported syz repro on 2023/10/01 22:16
Reported-by: syzbot+b8c4bd86b8f1fdc3605f@syzkaller.appspotmail.com
First crash: 147d, last: 147d

Sample crash report:
[  73.2620970] panic: ASan: Unauthorized Access In 0xffffffff81a82f19: Addr 0xffffc28013f6f182 [2 bytes, read, PoolRedZone]

[  73.2720958] cpu1: Begin traceback...
[  73.2921150] vpanic() at netbsd:vpanic+0x282 sys/kern/subr_prf.c:292
[  73.3620870] panic() at netbsd:panic+0x9e sys/kern/subr_prf.c:1088
[  73.4220853] kasan_report() at netbsd:kasan_report+0x8f kasan_code_name sys/kern/subr_asan.c:169 [inline]
[  73.4220853] kasan_report() at netbsd:kasan_report+0x8f sys/kern/subr_asan.c:201
[  73.4720852] __asan_load2() at netbsd:__asan_load2+0x8c kasan_shadow_2byte_isvalid sys/kern/subr_asan.c:331 [inline]
[  73.4720852] __asan_load2() at netbsd:__asan_load2+0x8c kasan_shadow_check sys/kern/subr_asan.c:415 [inline]
[  73.4720852] __asan_load2() at netbsd:__asan_load2+0x8c sys/kern/subr_asan.c:1206
[  73.5120848] ufs_rmdir() at netbsd:ufs_rmdir+0xc1 sys/ufs/ufs/ufs_vnops.c:1428
[  73.5620853] VOP_RMDIR() at netbsd:VOP_RMDIR+0x173 sys/kern/vnode_if.c:1382
[  73.6021031] union_rmdir() at netbsd:union_rmdir+0x15e sys/fs/union/union_vnops.c:1485
[  73.6420842] VOP_RMDIR() at netbsd:VOP_RMDIR+0x173 sys/kern/vnode_if.c:1382
[  73.6920846] do_sys_unlinkat() at netbsd:do_sys_unlinkat+0x64d sys/kern/vfs_syscalls.c:2890
[  73.7420886] syscall() at netbsd:syscall+0x25a sy_call sys/sys/syscallvar.h:65 [inline]
[  73.7420886] syscall() at netbsd:syscall+0x25a sy_invoke sys/sys/syscallvar.h:94 [inline]
[  73.7420886] syscall() at netbsd:syscall+0x25a sys/arch/x86/x86/syscall.c:138
[  73.7521133] --- syscall (number 137) ---
[  73.7721031] netbsd:syscall+0x25a:
[  73.7721031] cpu1: End traceback...
[  73.7820894] fatal breakpoint trap in supervisor mode
[  73.7820894] trap type 1 code 0 rip 0xffffffff8023241d cs 0x8 rflags 0x286 cr2 0x7f7fffd56fe0 ilevel 0 rsp 0xffffc282486c4960
[  73.7920830] curlwp 0xffffc28012ad30c0 pid 2024.2024 lowest kstack 0xffffc282486bd2c0
Stopped in pid 2024.2024 (syz-executor.4) at    netbsd:breakpoint+0x5:  leave
?
breakpoint() at netbsd:breakpoint+0x5
db_panic() at netbsd:db_panic+0x105 sys/ddb/db_panic.c:69
vpanic() at netbsd:vpanic+0x282 sys/kern/subr_prf.c:292
panic() at netbsd:panic+0x9e sys/kern/subr_prf.c:1088
kasan_report() at netbsd:kasan_report+0x8f kasan_code_name sys/kern/subr_asan.c:169 [inline]
kasan_report() at netbsd:kasan_report+0x8f sys/kern/subr_asan.c:201
__asan_load2() at netbsd:__asan_load2+0x8c kasan_shadow_2byte_isvalid sys/kern/subr_asan.c:331 [inline]
__asan_load2() at netbsd:__asan_load2+0x8c kasan_shadow_check sys/kern/subr_asan.c:415 [inline]
__asan_load2() at netbsd:__asan_load2+0x8c sys/kern/subr_asan.c:1206
ufs_rmdir() at netbsd:ufs_rmdir+0xc1 sys/ufs/ufs/ufs_vnops.c:1428
VOP_RMDIR() at netbsd:VOP_RMDIR+0x173 sys/kern/vnode_if.c:1382
union_rmdir() at netbsd:union_rmdir+0x15e sys/fs/union/union_vnops.c:1485
VOP_RMDIR() at netbsd:VOP_RMDIR+0x173 sys/kern/vnode_if.c:1382
do_sys_unlinkat() at netbsd:do_sys_unlinkat+0x64d sys/kern/vfs_syscalls.c:2890
syscall() at netbsd:syscall+0x25a sy_call sys/sys/syscallvar.h:65 [inline]
syscall() at netbsd:syscall+0x25a sy_invoke sys/sys/syscallvar.h:94 [inline]
syscall() at netbsd:syscall+0x25a sys/arch/x86/x86/syscall.c:138
--- syscall (number 137) ---
netbsd:syscall+0x25a:
Panic string: ASan: Unauthorized Access In 0xffffffff81a82f19: Addr 0xffffc28013f6f182 [2 bytes, read, PoolRedZone]

PID    LID S CPU     FLAGS       STRUCT LWP *               NAME WAIT
1977  2087 3   0         0   ffffc28012d27b00     syz-executor.0 tstile
1977  2122 3   0         0   ffffc280133a3180     syz-executor.0 tstile
1977  1977 2   0  10000000   ffffc28012c28680     syz-executor.0
1099  1099 2   0     40000   ffffc28012cfe600     syz-executor.0
2024 >2024 7   1        40   ffffc28012ad30c0     syz-executor.4
942   1205 2   1       100   ffffc28013dc1b40       syz-execprog
942    941 3   0       180   ffffc28013d13a80       syz-execprog parked
942   1237 3   1       180   ffffc28013d13640       syz-execprog wait
942    930 3   1       180   ffffc28013d13200       syz-execprog parked
942   1245 3   1       180   ffffc28013d0fa40       syz-execprog parked
942    991 3   0       180   ffffc28013d0f600       syz-execprog parked
942   1240 3   0       180   ffffc28013d0f1c0       syz-execprog wait
942   1242 3   1       180   ffffc28012c7ab80       syz-execprog parked
942   1067 3   1       180   ffffc28012bcf180       syz-execprog parked
942    829 2   1       140   ffffc28013431700       syz-execprog
942   1244 3   0       180   ffffc280134312c0       syz-execprog parked
942  > 449 7   0       140   ffffc280133d4ac0       syz-execprog
942    942 3   1       180   ffffc28012b7a100       syz-execprog parked
1080  1080 3   0       180   ffffc28012b7a540               sshd select
1224  1224 3   0       180   ffffc280126eb780              getty nanoslp
1216  1216 3   1       180   ffffc280126eb340              getty nanoslp
1225  1225 3   1       180   ffffc280134b65c0              getty nanoslp
1184  1184 3   0       1c0   ffffc280134b6180              getty ttyraw
1103  1103 3   0       180   ffffc280133b7600               sshd select
954    954 3   0       180   ffffc28012d82040             powerd kqueue
876    876 3   0       180   ffffc28012d45b80            syslogd kqueue
559    559 3   0       180   ffffc28012c28ac0             dhcpcd poll
746    746 3   1       180   ffffc28012cd1100             dhcpcd poll
745    745 3   0       180   ffffc28012c386c0             dhcpcd poll
599    599 3   0       180   ffffc28012c94bc0             dhcpcd poll
487    487 3   0       180   ffffc28012dc70c0             dhcpcd poll
292    292 3   0       180   ffffc28012dad900             dhcpcd poll
485    485 3   0       180   ffffc28012dad4c0             dhcpcd poll
1        1 3   0       180   ffffc28012879180               init wait
0      673 3   0       200   ffffc280129a26c0            physiod physiod
0      196 3   1       200   ffffc280129a4700          pooldrain pooldrain
0      195 3   0       240   ffffc280129a42c0            ioflush tstile
0      194 3   0       200   ffffc280129a2b00           pgdaemon pgdaemon
0      169 3   0       200   ffffc28012962ac0               usb7 usbevt
0      172 3   0       200   ffffc28012962680               usb6 usbevt
0      170 3   0       200   ffffc28012962240               usb5 usbevt
0      168 3   0       200   ffffc28012914a80               usb4 usbevt
0      166 3   0       200   ffffc28012914640               usb3 usbevt
0      165 3   0       200   ffffc28012914200               usb2 usbevt
0       31 3   0       200   ffffc280128daa40               usb1 usbevt
0       63 3   0       200   ffffc280128da600               usb0 usbevt
0      126 3   1       200   ffffc280128da1c0         usbtask-dr usbtsk
0      125 3   1       200   ffffc28012879a00         usbtask-hc usbtsk
0      124 3   0       200   ffffc28010d77b00          swwreboot swwreboot
0      123 3   0       200   ffffc280128795c0             npfgc0 npfgcw
0      122 3   1       200   ffffc2801286b9c0            rt_free rt_free
0      121 3   1       200   ffffc2801286b580              unpgc unpgc
0      120 3   0       200   ffffc2801286b140    key_timehandler key_timehandler
0      119 3   1       200   ffffc2801271c980    icmp6_wqinput/1 icmp6_wqinput
0      118 3   0       200   ffffc2801271c540    icmp6_wqinput/0 icmp6_wqinput
0      117 3   0       200   ffffc2801271c100          nd6_timer nd6_timer
0      116 3   1       200   ffffc28012713940    carp6_wqinput/1 carp6_wqinput
0      115 3   0       200   ffffc28012713500    carp6_wqinput/0 carp6_wqinput
0      114 3   1       200   ffffc280127130c0     carp_wqinput/1 carp_wqinput
0      113 3   0       200   ffffc28012705900     carp_wqinput/0 carp_wqinput
0      112 3   1       200   ffffc280127054c0     icmp_wqinput/1 icmp_wqinput
0      111 3   0       200   ffffc28012705080     icmp_wqinput/0 icmp_wqinput
0      110 3   0       200   ffffc280126e8b80           rt_timer rt_timer
0      109 3   0       200   ffffc280126ec8c0        vmem_rehash vmem_rehash
0      100 3   0       200   ffffc280126e8300          entbutler entropy
0       99 3   1       200   ffffc280120beb40              viomb balloon
0       98 3   1       200   ffffc280120be700      vioif0_txrx/1 vioif0_txrx
0       97 3   0       200   ffffc280120be2c0      vioif0_txrx/0 vioif0_txrx
0       30 3   0       200   ffffc28010d776c0           scsibus0 sccomp
0       29 3   0       200   ffffc28010d77280               pms0 pmsreset
0       28 3   1       200   ffffc28010cbdac0            xcall/1 xcall
0       27 1   1       200   ffffc28010cbd680          softser/1
0       26 1   1       200   ffffc28010cbd240          softclk/1
0       25 1   1       200   ffffc28010cb9a80          softbio/1
0       24 1   1       200   ffffc28010cb9640          softnet/1
0       23 1   1       201   ffffc28010cb9200             idle/1
0       22 3   0       200   ffffc2800f756a40           lnxsyswq lnxsyswq
0       21 3   0       200   ffffc2800f756600           lnxubdwq lnxubdwq
0       20 3   0       200   ffffc2800f7561c0           lnxpwrwq lnxpwrwq
0       19 3   0       200   ffffc2800f755a00           lnxlngwq lnxlngwq
0       18 3   0       200   ffffc2800f7555c0           lnxhipwq lnxhipwq
0       17 3   0       200   ffffc2800f755180           lnxrcugc lnxrcugc
0       16 3   0       200   ffffc2800f74e9c0             sysmon smtaskq
0       15 3   0       200   ffffc2800f74e580         pmfsuspend pmfsuspend
0       14 3   0       200   ffffc2800f74e140           pmfevent pmfevent
0       13 3   0       200   ffffc2800f74b980         sopendfree sopendfr
0       12 3   0       200   ffffc2800f74b540             ifwdog ifwdog
0       11 3   1       200   ffffc2800f74b100            iflnkst iflnkst
0       10 3   0       200   ffffc2800f73e940           nfssilly nfssilly
0        9 3   0       200   ffffc2800f73e500             vdrain vdrain
0        8 3   1       200   ffffc2800f73e0c0          modunload mod_unld
0        7 3   0       200   ffffc2800f733900            xcall/0 xcall
0        6 1   0       200   ffffc2800f7334c0          softser/0
0        5 1   0       200   ffffc2800f733080          softclk/0
0        4 1   0       200   ffffc2800f7318c0          softbio/0
0        3 1   0       200   ffffc2800f731480          softnet/0
0        2 1   0       201   ffffc2800f731040             idle/0
0        0 3   0       200   ffffffff83343700            swapper uvm
[Locks tracked through LWPs]

****** LWP 1099.1099 (syz-executor.0) @ 0xffffc28012cfe600, l_stat=2

*** Locks held:

* Lock 0 (initialized at netbsd:amap_ctor+0x39 sys/uvm/uvm_amap.c:265)
lock address : ffffc28013cf5a00
type         : sleep/adaptive
initialized  : netbsd:amap_ctor+0x39
shared holds :                  0 exclusive:                  1
shares wanted:                  0 exclusive:                  0
relevant cpu :                  0 last held:                  0
relevant lwp : 0xffffc28012cfe600 last held: 0xffffc28012cfe600
last locked* : netbsd:uvm_fault_internal+0x88a
unlocked     : netbsd:uvm_fault_upper_enter+0x366
owner/count  : 000000000000000000 flags    : 000000000000000000
Turnstile: no active turnstile for this lock.

*** Locks wanted: none

****** LWP 2024.2024 (syz-executor.4) @ 0xffffc28012ad30c0, l_stat=7

*** Locks held:

* Lock 0 (initialized at netbsd:vcache_alloc+0x3e sys/kern/vfs_vnode.c:1376)
lock address : ffffc28013ff4cc0
type         : sleep/adaptive
initialized  : netbsd:vcache_alloc+0x3e
shared holds :                  0 exclusive:                  1
shares wanted:                  0 exclusive:                  0
relevant cpu :                  1 last held:                  1
relevant lwp : 0xffffc28012ad30c0 last held: 0xffffc28012ad30c0
last locked* : netbsd:genfs_lock+0x160
unlocked     : netbsd:genfs_unlock+0x2a
owner/count  : 0xffffc28012ad30c0 flags    : 0x0000000000000004
Turnstile: no active turnstile for this lock.

* Lock 1 (initialized at netbsd:vcache_alloc+0x3e sys/kern/vfs_vnode.c:1376)
lock address : ffffc28013ff8200
type         : sleep/adaptive
initialized  : netbsd:vcache_alloc+0x3e
shared holds :                  0 exclusive:                  1
shares wanted:                  0 exclusive:                  0
relevant cpu :                  1 last held:                  1
relevant lwp : 0xffffc28012ad30c0 last held: 0xffffc28012ad30c0
last locked* : netbsd:genfs_lock+0x160
unlocked     : netbsd:genfs_unlock+0x2a
owner/count  : 0xffffc28012ad30c0 flags    : 0x0000000000000004
Turnstile: no active turnstile for this lock.

*** Locks wanted: none

****** LWP 942.1205 (syz-execprog) @ 0xffffc28013dc1b40, l_stat=2

*** Locks held: none

*** Locks wanted:

* Lock 0 (initialized at netbsd:vcache_alloc+0x4a sys/kern/vfs_vnode.c:1376)
lock address : ffffc28013fbbd40
type         : sleep/adaptive
initialized  : netbsd:vcache_alloc+0x4a
shared holds :                  0 exclusive:                  0
shares wanted:                  0 exclusive:                  1
relevant cpu :                  1 last held:                  1
relevant lwp : 0xffffc28013dc1b40 last held: 000000000000000000
last locked  : netbsd:vput+0xee
unlocked*    : netbsd:vrelel+0x4ee
owner field  : 0xffffc28013dc1b40 wait/spin:                1/0
Turnstile:
=> 0 waiting readers:
=> 1 waiting writers: 0xffffc280129a42c0

****** LWP 746.746 (dhcpcd) @ 0xffffc28012cd1100, l_stat=3

*** Locks held: none

*** Locks wanted:

* Lock 0 (initialized at netbsd:module_hook_init+0x1c sys/kern/kern_module_hook.c:132)
lock address : netbsd:module_hook
type         : sleep/adaptive
initialized  : netbsd:module_hook_init+0x1c
shared holds :                  0 exclusive:                  0
shares wanted:                  0 exclusive:                  0
relevant cpu :                  1 last held:                  0
relevant lwp : 0xffffc28012cd1100 last held: 000000000000000000
last locked  : 0
unlocked*    : 0
owner field  : 000000000000000000 wait/spin:                0/0
Turnstile: no active turnstile for this lock.

****** LWP 745.745 (dhcpcd) @ 0xffffc28012c386c0, l_stat=3

*** Locks held: none

*** Locks wanted:

* Lock 0 (initialized at netbsd:module_hook_init+0x1c sys/kern/kern_module_hook.c:132)
lock address : netbsd:module_hook
type         : sleep/adaptive
initialized  : netbsd:module_hook_init+0x1c
shared holds :                  0 exclusive:                  0
shares wanted:                  0 exclusive:                  0
relevant cpu :                  0 last held:                  0
relevant lwp : 0xffffc28012c386c0 last held: 000000000000000000
last locked  : 0
unlocked*    : 0
owner field  : 000000000000000000 wait/spin:                0/0
Turnstile: no active turnstile for this lock.

****** LWP 292.292 (dhcpcd) @ 0xffffc28012dad900, l_stat=3

*** Locks held: none

*** Locks wanted:

* Lock 0 (initialized at netbsd:module_hook_init+0x1c sys/kern/kern_module_hook.c:132)
lock address : netbsd:module_hook
type         : sleep/adaptive
initialized  : netbsd:module_hook_init+0x1c
shared holds :                  0 exclusive:                  0
shares wanted:                  0 exclusive:                  0
relevant cpu :                  0 last held:                  0
relevant lwp : 0xffffc28012dad900 last held: 000000000000000000
last locked  : 0
unlocked*    : 0
owner field  : 000000000000000000 wait/spin:                0/0
Turnstile: no active turnstile for this lock.

****** LWP 485.485 (dhcpcd) @ 0xffffc28012dad4c0, l_stat=3

*** Locks held: none

*** Locks wanted:

* Lock 0 (initialized at netbsd:module_hook_init+0x1c sys/kern/kern_module_hook.c:132)
lock address : netbsd:module_hook
type         : sleep/adaptive
initialized  : netbsd:module_hook_init+0x1c
shared holds :                  0 exclusive:                  0
shares wanted:                  0 exclusive:                  0
relevant cpu :                  0 last held:                  0
relevant lwp : 0xffffc28012dad4c0 last held: 000000000000000000
last locked  : 0
unlocked*    : 0
owner field  : 000000000000000000 wait/spin:                0/0
Turnstile: no active turnstile for this lock.

****** LWP 0.11 (iflnkst) @ 0xffffc2800f74b100, l_stat=3

*** Locks held: none

*** Locks wanted:

* Lock 0 (initialized at netbsd:module_hook_init+0x1c sys/kern/kern_module_hook.c:132)
lock address : netbsd:module_hook
type         : sleep/adaptive
initialized  : netbsd:module_hook_init+0x1c
shared holds :                  0 exclusive:                  0
shares wanted:                  0 exclusive:                  0
relevant cpu :                  1 last held:                  0
relevant lwp : 0xffffc2800f74b100 last held: 000000000000000000
last locked  : 0
unlocked*    : 0
owner field  : 000000000000000000 wait/spin:                0/0
Turnstile: no active turnstile for this lock.

****** LWP 0.5 (softclk/0) @ 0xffffc2800f733080, l_stat=1

*** Locks held: none

*** Locks wanted:

* Lock 0 (initialized at netbsd:module_hook_init+0x1c sys/kern/kern_module_hook.c:132)
lock address : netbsd:module_hook
type         : sleep/adaptive
initialized  : netbsd:module_hook_init+0x1c
shared holds :                  0 exclusive:                  0
shares wanted:                  0 exclusive:                  0
relevant cpu :                  0 last held:                  0
relevant lwp : 0xffffc2800f733080 last held: 000000000000000000
last locked  : 0
unlocked*    : 0
owner field  : 000000000000000000 wait/spin:                0/0
Turnstile: no active turnstile for this lock.

****** LWP 0.0 (swapper) @ 0xffffffff83343700, l_stat=3

*** Locks held: none

*** Locks wanted:

* Lock 0 (initialized at netbsd:module_hook_init+0x1c sys/kern/kern_module_hook.c:132)
lock address : netbsd:module_hook
type         : sleep/adaptive
initialized  : netbsd:module_hook_init+0x1c
shared holds :                  0 exclusive:                  0
shares wanted:                  0 exclusive:                  0
relevant c

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/10/01 22:16 netbsd 23ee83f7c0ae 8e26a358 .config console log report syz [disk image] [netbsd.gdb] ci2-netbsd ASan: Unauthorized Access in ufs_rmdir
* Struck through repros no longer work on HEAD.