[syzbot] [9p?] KASAN: wild-memory-access Write in v9fs_get_acl

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 596b6b709632 Merge branch 'for-next/core' into for-kernelci
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=12ce3de4c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=3519974f3f27816d
dashboard link: https://syzkaller.appspot.com/bug?extid=cb1d16facb3cc90de5fb
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15b2e204c80000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17e74fb0c80000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/06e2210b88a3/disk-596b6b70.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/79e6930ab577/vmlinux-596b6b70.xz
kernel image: https://storage.googleapis.com/syzbot-assets/56b95e6bcb5c/Image-596b6b70.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/e12043e9faac/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cb1d16...@syzkaller.appspotmail.com

loop0: detected capacity change from 0 to 256
MINIX-fs: mounting unchecked file system, running fsck is recommended
==================================================================
BUG: KASAN: wild-memory-access in instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
BUG: KASAN: wild-memory-access in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176 [inline]
BUG: KASAN: wild-memory-access in __refcount_sub_and_test include/linux/refcount.h:272 [inline]
BUG: KASAN: wild-memory-access in __refcount_dec_and_test include/linux/refcount.h:315 [inline]
BUG: KASAN: wild-memory-access in refcount_dec_and_test include/linux/refcount.h:333 [inline]
BUG: KASAN: wild-memory-access in posix_acl_release include/linux/posix_acl.h:57 [inline]
BUG: KASAN: wild-memory-access in v9fs_get_acl+0x1a4/0x390 fs/9p/acl.c:102
Write of size 4 at addr 9fffeb37f97f1c00 by task syz-executor798/5923

CPU: 0 PID: 5923 Comm: syz-executor798 Not tainted 6.2.0-syzkaller-18302-g596b6b709632 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
Call trace:
dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
print_report+0xe4/0x4c0 mm/kasan/report.c:420
kasan_report+0xd4/0x130 mm/kasan/report.c:517
kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:189
__kasan_check_write+0x2c/0x3c mm/kasan/shadow.c:37
instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176 [inline]
__refcount_sub_and_test include/linux/refcount.h:272 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
posix_acl_release include/linux/posix_acl.h:57 [inline]
v9fs_get_acl+0x1a4/0x390 fs/9p/acl.c:102
v9fs_mount+0x77c/0xa5c fs/9p/vfs_super.c:183
legacy_get_tree+0xd4/0x16c fs/fs_context.c:610
vfs_get_tree+0x90/0x274 fs/super.c:1489
do_new_mount+0x25c/0x8c8 fs/namespace.c:3145
path_mount+0x590/0xe58 fs/namespace.c:3475
do_mount fs/namespace.c:3488 [inline]
__do_sys_mount fs/namespace.c:3697 [inline]
__se_sys_mount fs/namespace.c:3674 [inline]
__arm64_sys_mount+0x45c/0x594 fs/namespace.c:3674
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
==================================================================
Unable to handle kernel paging request at virtual address 9fffeb37f97f1c00
Mem abort info:
ESR = 0x0000000096000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
Data abort info:
ISV = 0, ISS = 0x00000004
CM = 0, WnR = 0
[9fffeb37f97f1c00] address between user and kernel address ranges
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 5923 Comm: syz-executor798 Tainted: G B 6.2.0-syzkaller-18302-g596b6b709632 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __lse_atomic_fetch_add_release arch/arm64/include/asm/atomic_lse.h:62 [inline]
pc : __lse_atomic_fetch_sub_release arch/arm64/include/asm/atomic_lse.h:76 [inline]
pc : arch_atomic_fetch_sub_release arch/arm64/include/asm/atomic.h:51 [inline]
pc : atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:177 [inline]
pc : __refcount_sub_and_test include/linux/refcount.h:272 [inline]
pc : __refcount_dec_and_test include/linux/refcount.h:315 [inline]
pc : refcount_dec_and_test include/linux/refcount.h:333 [inline]
pc : posix_acl_release include/linux/posix_acl.h:57 [inline]
pc : v9fs_get_acl+0x1b0/0x390 fs/9p/acl.c:102
lr : arch_atomic_fetch_sub_release arch/arm64/include/asm/atomic.h:51 [inline]
lr : atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:177 [inline]
lr : __refcount_sub_and_test include/linux/refcount.h:272 [inline]
lr : __refcount_dec_and_test include/linux/refcount.h:315 [inline]
lr : refcount_dec_and_test include/linux/refcount.h:333 [inline]
lr : posix_acl_release include/linux/posix_acl.h:57 [inline]
lr : v9fs_get_acl+0x1ac/0x390 fs/9p/acl.c:102
sp : ffff80001e607970
x29: ffff80001e607970 x28: dfff800000000000 x27: 1ffff00003cc0f3c
x26: 1ffff00003cc0f38 x25: ffff0000ddbe4648 x24: ffff0000ddbe45e0
x23: ffff0000de2a0000 x22: dfff800000000000 x21: 9fffeb37f97f1c00
x20: 00000000fffffffb x19: fffffffffffffffb x18: 1fffe0003689b776
x17: ffff800015b8d000 x16: ffff80001235d16c x15: 0000000000000000
x14: 0000000040000000 x13: 0000000000000002 x12: 0000000000000001
x11: ff80800009d500bc x10: 0000000000000000 x9 : ffff800009d500bc
x8 : 00000000ffffffff x7 : 1fffe0003689b777 x6 : ffff800008288c58
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff8000081b9ce8
x2 : 0000000000000001 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
arch_atomic_fetch_sub_release arch/arm64/include/asm/atomic.h:51 [inline]
atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:177 [inline]
__refcount_sub_and_test include/linux/refcount.h:272 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
posix_acl_release include/linux/posix_acl.h:57 [inline]
v9fs_get_acl+0x1b0/0x390 fs/9p/acl.c:102
v9fs_mount+0x77c/0xa5c fs/9p/vfs_super.c:183
legacy_get_tree+0xd4/0x16c fs/fs_context.c:610
vfs_get_tree+0x90/0x274 fs/super.c:1489
do_new_mount+0x25c/0x8c8 fs/namespace.c:3145
path_mount+0x590/0xe58 fs/namespace.c:3475
do_mount fs/namespace.c:3488 [inline]
__do_sys_mount fs/namespace.c:3697 [inline]
__se_sys_mount fs/namespace.c:3674 [inline]
__arm64_sys_mount+0x45c/0x594 fs/namespace.c:3674
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
Code: 97b08d5c d503201f 979ee91f 12800008 (b86802b6)
---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):
0: 97b08d5c bl 0xfffffffffec23570
4: d503201f nop
8: 979ee91f bl 0xfffffffffe7ba484
c: 12800008 mov w8, #0xffffffff // #-1
* 10: b86802b6 ldaddl w8, w22, [x21] <-- trapping instruction


---
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syzbot can test patches for this issue, for details see:
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[syzbot]

> #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git

want 2 args (repo, branch), got 1

[Ivan Orlov]

#syz test
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

[Ivan Orlov]

On 3/11/23 11:21, syzbot wrote:
>> #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>
> want 2 args (repo, branch), got 1
>

#syz test:
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: wild-memory-access Write in v9fs_get_acl

loop0: detected capacity change from 0 to 256
MINIX-fs: mounting unchecked file system, running fsck is recommended
==================================================================
BUG: KASAN: wild-memory-access in instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
BUG: KASAN: wild-memory-access in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176 [inline]
BUG: KASAN: wild-memory-access in __refcount_sub_and_test include/linux/refcount.h:272 [inline]
BUG: KASAN: wild-memory-access in __refcount_dec_and_test include/linux/refcount.h:315 [inline]
BUG: KASAN: wild-memory-access in refcount_dec_and_test include/linux/refcount.h:333 [inline]
BUG: KASAN: wild-memory-access in posix_acl_release include/linux/posix_acl.h:57 [inline]
BUG: KASAN: wild-memory-access in v9fs_get_acl+0x1a4/0x390 fs/9p/acl.c:102

Write of size 4 at addr 9fffeb37f97f1c00 by task syz-executor.0/6490

CPU: 0 PID: 6490 Comm: syz-executor.0 Not tainted 6.3.0-rc1-syzkaller-00230-gef5f68cc1f82 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023

Call trace:
dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106

print_report+0xe4/0x514 mm/kasan/report.c:433
kasan_report+0xd4/0x130 mm/kasan/report.c:536
kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:187

__kasan_check_write+0x2c/0x3c mm/kasan/shadow.c:37
instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176 [inline]
__refcount_sub_and_test include/linux/refcount.h:272 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
posix_acl_release include/linux/posix_acl.h:57 [inline]
v9fs_get_acl+0x1a4/0x390 fs/9p/acl.c:102
v9fs_mount+0x77c/0xa5c fs/9p/vfs_super.c:183
legacy_get_tree+0xd4/0x16c fs/fs_context.c:610

vfs_get_tree+0x90/0x274 fs/super.c:1501
do_new_mount+0x25c/0x8c8 fs/namespace.c:3042
path_mount+0x590/0xe20 fs/namespace.c:3372
do_mount fs/namespace.c:3385 [inline]
__do_sys_mount fs/namespace.c:3594 [inline]
__se_sys_mount fs/namespace.c:3571 [inline]
__arm64_sys_mount+0x45c/0x594 fs/namespace.c:3571

__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
==================================================================
Unable to handle kernel paging request at virtual address 9fffeb37f97f1c00
Mem abort info:
ESR = 0x0000000096000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
Data abort info:
ISV = 0, ISS = 0x00000004
CM = 0, WnR = 0
[9fffeb37f97f1c00] address between user and kernel address ranges
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in:

CPU: 0 PID: 6490 Comm: syz-executor.0 Tainted: G B 6.3.0-rc1-syzkaller-00230-gef5f68cc1f82 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023

pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __lse_atomic_fetch_add_release arch/arm64/include/asm/atomic_lse.h:62 [inline]
pc : __lse_atomic_fetch_sub_release arch/arm64/include/asm/atomic_lse.h:76 [inline]
pc : arch_atomic_fetch_sub_release arch/arm64/include/asm/atomic.h:51 [inline]
pc : atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:177 [inline]
pc : __refcount_sub_and_test include/linux/refcount.h:272 [inline]
pc : __refcount_dec_and_test include/linux/refcount.h:315 [inline]
pc : refcount_dec_and_test include/linux/refcount.h:333 [inline]
pc : posix_acl_release include/linux/posix_acl.h:57 [inline]
pc : v9fs_get_acl+0x1b0/0x390 fs/9p/acl.c:102
lr : arch_atomic_fetch_sub_release arch/arm64/include/asm/atomic.h:51 [inline]
lr : atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:177 [inline]
lr : __refcount_sub_and_test include/linux/refcount.h:272 [inline]
lr : __refcount_dec_and_test include/linux/refcount.h:315 [inline]
lr : refcount_dec_and_test include/linux/refcount.h:333 [inline]
lr : posix_acl_release include/linux/posix_acl.h:57 [inline]
lr : v9fs_get_acl+0x1ac/0x390 fs/9p/acl.c:102

sp : ffff80001e837970
x29: ffff80001e837970 x28: dfff800000000000 x27: 1ffff00003d06f3c
x26: 1ffff00003d06f38 x25: ffff0000dd9041e0 x24: ffff0000dd904178
x23: ffff0000e5068000 x22: dfff800000000000 x21: 9fffeb37f97f1c00
x20: 00000000fffffffb x19: fffffffffffffffb x18: 1fffe000368951b6
x17: ffff800015cdd000 x16: ffff80001245e54c x15: 0000000000000000

x14: 0000000040000000 x13: 0000000000000002 x12: 0000000000000001

x11: ff80800009d819b8 x10: 0000000000000000 x9 : ffff800009d819b8
x8 : 00000000ffffffff x7 : 1fffe000368951b7 x6 : ffff80000828dc14
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff8000081bc3c4

x2 : 0000000000000001 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
arch_atomic_fetch_sub_release arch/arm64/include/asm/atomic.h:51 [inline]
atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:177 [inline]
__refcount_sub_and_test include/linux/refcount.h:272 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
posix_acl_release include/linux/posix_acl.h:57 [inline]
v9fs_get_acl+0x1b0/0x390 fs/9p/acl.c:102
v9fs_mount+0x77c/0xa5c fs/9p/vfs_super.c:183
legacy_get_tree+0xd4/0x16c fs/fs_context.c:610

vfs_get_tree+0x90/0x274 fs/super.c:1501
do_new_mount+0x25c/0x8c8 fs/namespace.c:3042
path_mount+0x590/0xe20 fs/namespace.c:3372
do_mount fs/namespace.c:3385 [inline]
__do_sys_mount fs/namespace.c:3594 [inline]
__se_sys_mount fs/namespace.c:3571 [inline]
__arm64_sys_mount+0x45c/0x594 fs/namespace.c:3571

__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591

Code: 97b021c6 d503201f 979e3dbf 12800008 (b86802b6)

---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):

0: 97b021c6 bl 0xfffffffffec08718
4: d503201f nop
8: 979e3dbf bl 0xfffffffffe78f704

c: 12800008 mov w8, #0xffffffff // #-1
* 10: b86802b6 ldaddl w8, w22, [x21] <-- trapping instruction

Tested on:

commit: ef5f68cc Merge tag 'scsi-fixes' of git://git.kernel.or..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=115a390ac80000
kernel config: https://syzkaller.appspot.com/x/.config?x=fd3c6e109ff25818

dashboard link: https://syzkaller.appspot.com/bug?extid=cb1d16facb3cc90de5fb
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

Note: no patches were applied.

[Ivan Orlov]

On 3/11/23 11:21, syzbot wrote:

>> #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>
> want 2 args (repo, branch), got 1
>

#syz test:
http://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git master

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: wild-memory-access Write in v9fs_get_acl

loop0: detected capacity change from 0 to 256
MINIX-fs: mounting unchecked file system, running fsck is recommended
==================================================================
BUG: KASAN: wild-memory-access in instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
BUG: KASAN: wild-memory-access in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176 [inline]
BUG: KASAN: wild-memory-access in __refcount_sub_and_test include/linux/refcount.h:272 [inline]
BUG: KASAN: wild-memory-access in __refcount_dec_and_test include/linux/refcount.h:315 [inline]
BUG: KASAN: wild-memory-access in refcount_dec_and_test include/linux/refcount.h:333 [inline]
BUG: KASAN: wild-memory-access in posix_acl_release include/linux/posix_acl.h:57 [inline]
BUG: KASAN: wild-memory-access in v9fs_get_acl+0x1a4/0x390 fs/9p/acl.c:102

Write of size 4 at addr 9fffeb37f97f1c00 by task syz-executor.0/6522

CPU: 0 PID: 6522 Comm: syz-executor.0 Not tainted 6.3.0-rc1-syzkaller-00230-gef5f68cc1f82 #0

CPU: 0 PID: 6522 Comm: syz-executor.0 Tainted: G B 6.3.0-rc1-syzkaller-00230-gef5f68cc1f82 #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __lse_atomic_fetch_add_release arch/arm64/include/asm/atomic_lse.h:62 [inline]
pc : __lse_atomic_fetch_sub_release arch/arm64/include/asm/atomic_lse.h:76 [inline]
pc : arch_atomic_fetch_sub_release arch/arm64/include/asm/atomic.h:51 [inline]
pc : atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:177 [inline]
pc : __refcount_sub_and_test include/linux/refcount.h:272 [inline]
pc : __refcount_dec_and_test include/linux/refcount.h:315 [inline]
pc : refcount_dec_and_test include/linux/refcount.h:333 [inline]
pc : posix_acl_release include/linux/posix_acl.h:57 [inline]
pc : v9fs_get_acl+0x1b0/0x390 fs/9p/acl.c:102
lr : arch_atomic_fetch_sub_release arch/arm64/include/asm/atomic.h:51 [inline]
lr : atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:177 [inline]
lr : __refcount_sub_and_test include/linux/refcount.h:272 [inline]
lr : __refcount_dec_and_test include/linux/refcount.h:315 [inline]
lr : refcount_dec_and_test include/linux/refcount.h:333 [inline]
lr : posix_acl_release include/linux/posix_acl.h:57 [inline]
lr : v9fs_get_acl+0x1ac/0x390 fs/9p/acl.c:102

sp : ffff80001e727970
x29: ffff80001e727970 x28: dfff800000000000 x27: 1ffff00003ce4f3c
x26: 1ffff00003ce4f38 x25: ffff0000dd6221e0 x24: ffff0000dd622178
x23: ffff0000e06d8000 x22: dfff800000000000 x21: 9fffeb37f97f1c00
x20: 00000000fffffffb x19: fffffffffffffffb x18: 0000000000000180
x17: 0000000000000000 x16: ffff80001245e54c x15: 0000000000000000
x14: 0000000000000000 x13: 0000000000000001 x12: 0000000000000001

x11: ff80800009d819b8 x10: 0000000000000000 x9 : ffff800009d819b8

x8 : 00000000ffffffff x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff80001e727178 x4 : ffff800015dc52c0 x3 : ffff8000081bc3c4

git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17df1db8c80000

[Ivan Orlov]

On 3/11/23 11:21, syzbot wrote:

>> #syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>
> want 2 args (repo, branch), got 1
>

#syz test:
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

--- a/fs/9p/xattr.c
+++ b/fs/9p/xattr.c
@@ -35,10 +35,14 @@ ssize_t v9fs_fid_xattr_get(struct p9_fid *fid, const
char *name,
return retval;
}
if (attr_size > buffer_size) {
- if (!buffer_size) /* request to get the attr_size */
- retval = attr_size;
- else
+ if (!buffer_size) {/* request to get the attr_size */
+ if (attr_size > SSIZE_MAX)
+ retval = -EOVERFLOW;
+ else
+ retval = attr_size;
+ } else {
retval = -ERANGE;
+ }
} else {
iov_iter_truncate(&to, attr_size);
retval = p9_client_read(attr_fid, 0, &to, &err);
--

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

failed to checkout kernel repo http://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/master: failed to run ["git" "fetch" "--force" "756e4585e7356bde1e82a2023e6840f97669e7a5" "master"]: exit status 128
warning: redirecting to https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/
fatal: couldn't find remote ref master



Tested on:

commit: [unknown
git tree: http://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git master

dashboard link: https://syzkaller.appspot.com/bug?extid=cb1d16facb3cc90de5fb
compiler:

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: wild-memory-access Write in v9fs_get_acl

loop0: detected capacity change from 0 to 256
MINIX-fs: mounting unchecked file system, running fsck is recommended
==================================================================
BUG: KASAN: wild-memory-access in instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
BUG: KASAN: wild-memory-access in atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176 [inline]
BUG: KASAN: wild-memory-access in __refcount_sub_and_test include/linux/refcount.h:272 [inline]
BUG: KASAN: wild-memory-access in __refcount_dec_and_test include/linux/refcount.h:315 [inline]
BUG: KASAN: wild-memory-access in refcount_dec_and_test include/linux/refcount.h:333 [inline]
BUG: KASAN: wild-memory-access in posix_acl_release include/linux/posix_acl.h:57 [inline]
BUG: KASAN: wild-memory-access in v9fs_get_acl+0x1a4/0x390 fs/9p/acl.c:102

Write of size 4 at addr 9fffeb37f97f1c00 by task syz-executor.0/6492

CPU: 0 PID: 6492 Comm: syz-executor.0 Not tainted 6.3.0-rc1-syzkaller-00230-gef5f68cc1f82 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023

Call trace:
dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106

print_report+0xe4/0x514 mm/kasan/report.c:433
kasan_report+0xd4/0x130 mm/kasan/report.c:536
kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:187

__kasan_check_write+0x2c/0x3c mm/kasan/shadow.c:37
instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:176 [inline]
__refcount_sub_and_test include/linux/refcount.h:272 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
posix_acl_release include/linux/posix_acl.h:57 [inline]
v9fs_get_acl+0x1a4/0x390 fs/9p/acl.c:102
v9fs_mount+0x77c/0xa5c fs/9p/vfs_super.c:183
legacy_get_tree+0xd4/0x16c fs/fs_context.c:610

vfs_get_tree+0x90/0x274 fs/super.c:1501
do_new_mount+0x25c/0x8c8 fs/namespace.c:3042
path_mount+0x590/0xe20 fs/namespace.c:3372
do_mount fs/namespace.c:3385 [inline]
__do_sys_mount fs/namespace.c:3594 [inline]
__se_sys_mount fs/namespace.c:3571 [inline]
__arm64_sys_mount+0x45c/0x594 fs/namespace.c:3571

__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591
==================================================================
Unable to handle kernel paging request at virtual address 9fffeb37f97f1c00
Mem abort info:
ESR = 0x0000000096000004
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x04: level 0 translation fault
Data abort info:
ISV = 0, ISS = 0x00000004
CM = 0, WnR = 0
[9fffeb37f97f1c00] address between user and kernel address ranges
Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
Modules linked in:

CPU: 0 PID: 6492 Comm: syz-executor.0 Tainted: G B 6.3.0-rc1-syzkaller-00230-gef5f68cc1f82 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023

pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __lse_atomic_fetch_add_release arch/arm64/include/asm/atomic_lse.h:62 [inline]
pc : __lse_atomic_fetch_sub_release arch/arm64/include/asm/atomic_lse.h:76 [inline]
pc : arch_atomic_fetch_sub_release arch/arm64/include/asm/atomic.h:51 [inline]
pc : atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:177 [inline]
pc : __refcount_sub_and_test include/linux/refcount.h:272 [inline]
pc : __refcount_dec_and_test include/linux/refcount.h:315 [inline]
pc : refcount_dec_and_test include/linux/refcount.h:333 [inline]
pc : posix_acl_release include/linux/posix_acl.h:57 [inline]
pc : v9fs_get_acl+0x1b0/0x390 fs/9p/acl.c:102
lr : arch_atomic_fetch_sub_release arch/arm64/include/asm/atomic.h:51 [inline]
lr : atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:177 [inline]
lr : __refcount_sub_and_test include/linux/refcount.h:272 [inline]
lr : __refcount_dec_and_test include/linux/refcount.h:315 [inline]
lr : refcount_dec_and_test include/linux/refcount.h:333 [inline]
lr : posix_acl_release include/linux/posix_acl.h:57 [inline]
lr : v9fs_get_acl+0x1ac/0x390 fs/9p/acl.c:102

sp : ffff80001e627970
x29: ffff80001e627970 x28: dfff800000000000 x27: 1ffff00003cc4f3c
x26: 1ffff00003cc4f38 x25: ffff0000ccae3ad8 x24: ffff0000ccae3a70
x23: ffff0000e0a28000 x22: dfff800000000000 x21: 9fffeb37f97f1c00

x20: 00000000fffffffb x19: fffffffffffffffb x18: 1fffe000368951b6

x17: ffff800015cdd000 x16: ffff80001245e54c x15: 0000000000000000

x14: 0000000040000000 x13: 0000000000000002 x12: 0000000000000001

x11: ff80800009d819b8 x10: 0000000000000000 x9 : ffff800009d819b8

x8 : 00000000ffffffff x7 : 1fffe000368951b7 x6 : ffff80000828dc14
x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff8000081bc3c4

x2 : 0000000000000001 x1 : 0000000000000000 x0 : 0000000000000000
Call trace:
arch_atomic_fetch_sub_release arch/arm64/include/asm/atomic.h:51 [inline]
atomic_fetch_sub_release include/linux/atomic/atomic-instrumented.h:177 [inline]
__refcount_sub_and_test include/linux/refcount.h:272 [inline]
__refcount_dec_and_test include/linux/refcount.h:315 [inline]
refcount_dec_and_test include/linux/refcount.h:333 [inline]
posix_acl_release include/linux/posix_acl.h:57 [inline]
v9fs_get_acl+0x1b0/0x390 fs/9p/acl.c:102
v9fs_mount+0x77c/0xa5c fs/9p/vfs_super.c:183
legacy_get_tree+0xd4/0x16c fs/fs_context.c:610

vfs_get_tree+0x90/0x274 fs/super.c:1501
do_new_mount+0x25c/0x8c8 fs/namespace.c:3042
path_mount+0x590/0xe20 fs/namespace.c:3372
do_mount fs/namespace.c:3385 [inline]
__do_sys_mount fs/namespace.c:3594 [inline]
__se_sys_mount fs/namespace.c:3571 [inline]
__arm64_sys_mount+0x45c/0x594 fs/namespace.c:3571

__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:193
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591

Code: 97b021c6 d503201f 979e3dbf 12800008 (b86802b6)

---[ end trace 0000000000000000 ]---
----------------
Code disassembly (best guess):

0: 97b021c6 bl 0xfffffffffec08718
4: d503201f nop
8: 979e3dbf bl 0xfffffffffe78f704

c: 12800008 mov w8, #0xffffffff // #-1
* 10: b86802b6 ldaddl w8, w22, [x21] <-- trapping instruction

Tested on:

commit: ef5f68cc Merge tag 'scsi-fixes' of git://git.kernel.or..

git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

console output: https://syzkaller.appspot.com/x/log.txt?x=11669242c80000
kernel config: https://syzkaller.appspot.com/x/.config?x=fd3c6e109ff25818

dashboard link: https://syzkaller.appspot.com/bug?extid=cb1d16facb3cc90de5fb
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+cb1d16...@syzkaller.appspotmail.com

Tested on:

commit: ef5f68cc Merge tag 'scsi-fixes' of git://git.kernel.or..

git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=115eb2c6c80000

kernel config: https://syzkaller.appspot.com/x/.config?x=fd3c6e109ff25818
dashboard link: https://syzkaller.appspot.com/bug?extid=cb1d16facb3cc90de5fb
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

patch: https://syzkaller.appspot.com/x/patch.diff?x=1201e5dac80000

Note: testing is done by a robot and is best-effort only.

[Ivan Orlov]

#syz test:
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master

--- a/fs/9p/xattr.c
+++ b/fs/9p/xattr.c

@@ -35,10 +35,12 @@ ssize_t v9fs_fid_xattr_get(struct p9_fid *fid, const

char *name,
return retval;
}
if (attr_size > buffer_size) {
- if (!buffer_size) /* request to get the attr_size */
- retval = attr_size;
- else

+ if (buffer_size)
retval = -ERANGE;
+ else if (attr_size > SSIZE_MAX)
+ retval = -EOVERFLOW;
+ else /* request to get the attr_size */
+ retval = attr_size;

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+cb1d16...@syzkaller.appspotmail.com

Tested on:

commit: ef5f68cc Merge tag 'scsi-fixes' of git://git.kernel.or..
git tree: upstream

console output: https://syzkaller.appspot.com/x/log.txt?x=117c20c6c80000

kernel config: https://syzkaller.appspot.com/x/.config?x=fd3c6e109ff25818
dashboard link: https://syzkaller.appspot.com/bug?extid=cb1d16facb3cc90de5fb
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: arm64

patch: https://syzkaller.appspot.com/x/patch.diff?x=1033c4dac80000