* KASAN: slab-out-of-bounds Read in squashfs_get_id
@ 2020-09-25 14:48 syzbot
2020-10-14 7:52 ` Fox Chen
2021-03-11 11:23 ` [syzbot] " syzbot
0 siblings, 2 replies; 4+ messages in thread
From: syzbot @ 2020-09-25 14:48 UTC (permalink / raw)
To: linux-kernel, phillip, syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: 171d4ff7 Merge tag 'mmc-v5.9-rc4-2' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1597ead3900000
kernel config: https://syzkaller.appspot.com/x/.config?x=af502ec9a451c9fc
dashboard link: https://syzkaller.appspot.com/bug?extid=8e28bba73ed1772a6802
compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=172ff481900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17c3e6c5900000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8e28bba73ed1772a6802@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: slab-out-of-bounds in squashfs_get_id+0xb9/0x1c0 fs/squashfs/id.c:38
Read of size 8 at addr ffff8880a9684b98 by task syz-executor329/6836
CPU: 1 PID: 6836 Comm: syz-executor329 Not tainted 5.9.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1d6/0x29e lib/dump_stack.c:118
print_address_description+0x66/0x620 mm/kasan/report.c:383
__kasan_report mm/kasan/report.c:513 [inline]
kasan_report+0x132/0x1d0 mm/kasan/report.c:530
squashfs_get_id+0xb9/0x1c0 fs/squashfs/id.c:38
squashfs_new_inode fs/squashfs/inode.c:51 [inline]
squashfs_read_inode+0x155/0x2170 fs/squashfs/inode.c:120
squashfs_fill_super+0x1478/0x1790 fs/squashfs/super.c:310
get_tree_bdev+0x3e9/0x5f0 fs/super.c:1342
vfs_get_tree+0x88/0x270 fs/super.c:1547
do_new_mount fs/namespace.c:2875 [inline]
path_mount+0x179d/0x29e0 fs/namespace.c:3192
do_mount fs/namespace.c:3205 [inline]
__do_sys_mount fs/namespace.c:3413 [inline]
__se_sys_mount+0x126/0x180 fs/namespace.c:3390
do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x446d1a
Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 fd ad fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 da ad fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007ffd7dd4f8b8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffd7dd4f910 RCX: 0000000000446d1a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007ffd7dd4f8d0
RBP: 00007ffd7dd4f8d0 R08: 00007ffd7dd4f910 R09: 00007ffd00000015
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 0000000000000004 R14: 0000000000000003 R15: 0000000000000003
Allocated by task 3913:
kasan_save_stack mm/kasan/common.c:48 [inline]
kasan_set_track mm/kasan/common.c:56 [inline]
__kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461
kmalloc_node include/linux/slab.h:577 [inline]
__vmalloc_area_node mm/vmalloc.c:2429 [inline]
__vmalloc_node_range+0x2c7/0x870 mm/vmalloc.c:2511
module_alloc+0x7e/0x90 arch/x86/kernel/module.c:75
bpf_jit_binary_alloc+0x123/0x230 kernel/bpf/core.c:871
bpf_int_jit_compile+0x7995/0x8920 arch/x86/net/bpf_jit_comp.c:1911
bpf_prog_select_runtime+0x76d/0xa60 kernel/bpf/core.c:1807
bpf_migrate_filter net/core/filter.c:1290 [inline]
bpf_prepare_filter+0xec2/0x1140 net/core/filter.c:1338
bpf_prog_create_from_user+0x2ad/0x3e0 net/core/filter.c:1432
seccomp_prepare_filter kernel/seccomp.c:567 [inline]
seccomp_prepare_user_filter kernel/seccomp.c:604 [inline]
seccomp_set_mode_filter kernel/seccomp.c:1546 [inline]
do_seccomp+0x852/0x20b0 kernel/seccomp.c:1661
do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The buggy address belongs to the object at ffff8880a9684b80
which belongs to the cache kmalloc-32 of size 32
The buggy address is located 24 bytes inside of
32-byte region [ffff8880a9684b80, ffff8880a9684ba0)
The buggy address belongs to the page:
page:00000000f697ca3d refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880a9684fc1 pfn:0xa9684
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002a5d5c8 ffffea0002a98588 ffff8880aa440100
raw: ffff8880a9684fc1 ffff8880a9684000 000000010000003f 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8880a9684a80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
ffff8880a9684b00: 00 fc fc fc fc fc fc fc fa fb fb fb fc fc fc fc
>ffff8880a9684b80: 00 fc fc fc fc fc fc fc fa fb fb fb fc fc fc fc
^
ffff8880a9684c00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
ffff8880a9684c80: 00 00 01 fc fc fc fc fc fa fb fb fb fc fc fc fc
==================================================================
---
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See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
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syzbot can test patches for this issue, for details see:
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: KASAN: slab-out-of-bounds Read in squashfs_get_id
2020-09-25 14:48 KASAN: slab-out-of-bounds Read in squashfs_get_id syzbot
@ 2020-10-14 7:52 ` Fox Chen
2021-03-11 11:23 ` [syzbot] " syzbot
1 sibling, 0 replies; 4+ messages in thread
From: Fox Chen @ 2020-10-14 7:52 UTC (permalink / raw)
To: phillip, syzkaller-bugs; +Cc: linux-kernel, gregkh
Hi,
I found this bug was caused by either uid/gid info in superblocks or
id_index_table is corrupted. The uid/gid index is larger than the size
of msblk->id_table.
Should I add a sanity check to squashfs_get_id??
The complete solution is to record the size of msblk->id_table in msblk
and check uid/gid index each time in squashfs_get_id. However, this
requires a change to msblk struct.
A simple solution is to calculate the max available room for uid/gid
table by doing msblk->xattr_table - msblk->id_table[0] and check if
index is larger than this. While this provides some sort of check, it is
imperfect because id_table can be smaller than that.
Both of them work out for this bug.
thanks,
fox
On Friday, September 25, 2020 at 10:48:18 PM UTC+8 syzbot wrote:
Hello,
syzbot found the following issue on:
HEAD commit: 171d4ff7 Merge tag 'mmc-v5.9-rc4-2' of
git://git.kernel.or.. git tree: upstream console output:
https://syzkaller.appspot.com/x/log.txt?x=1597ead3900000 kernel config:
https://syzkaller.appspot.com/x/.config?x=af502ec9a451c9fc dashboard
link: https://syzkaller.appspot.com/bug?extid=8e28bba73ed1772a6802
compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/
c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro:
https://syzkaller.appspot.com/x/repro.syz?x=172ff481900000 C reproducer:
https://syzkaller.appspot.com/x/repro.c?x=17c3e6c5900000
IMPORTANT: if you fix the issue, please add the following tag to the
commit: Reported-by: syzbot+8e28bb...@syzkaller.appspotmail.com
================================================================== BUG:
KASAN: slab-out-of-bounds in squashfs_get_id+0xb9/0x1c0
fs/squashfs/id.c:38 Read of size 8 at addr ffff8880a9684b98 by task
syz-executor329/6836
CPU: 1 PID: 6836 Comm: syz-executor329 Not tainted 5.9.0-rc6-syzkaller
#0 Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77
[inline] dump_stack+0x1d6/0x29e lib/dump_stack.c:118
print_address_description+0x66/0x620 mm/kasan/report.c:383
__kasan_report mm/kasan/report.c:513 [inline] kasan_report+0x132/0x1d0
mm/kasan/report.c:530 squashfs_get_id+0xb9/0x1c0 fs/squashfs/id.c:38
squashfs_new_inode fs/squashfs/inode.c:51 [inline]
squashfs_read_inode+0x155/0x2170 fs/squashfs/inode.c:120
squashfs_fill_super+0x1478/0x1790 fs/squashfs/super.c:310
get_tree_bdev+0x3e9/0x5f0 fs/super.c:1342 vfs_get_tree+0x88/0x270
fs/super.c:1547 do_new_mount fs/namespace.c:2875 [inline]
path_mount+0x179d/0x29e0 fs/namespace.c:3192 do_mount
fs/namespace.c:3205 [inline] __do_sys_mount fs/namespace.c:3413 [inline]
__se_sys_mount+0x126/0x180 fs/namespace.c:3390 do_syscall_64+0x31/0x70
arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP:
0033:0x446d1a Code: b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 fd ad
fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 49 89 ca b8 a5 00 00 00 0f
05 <48> 3d 01 f0 ff ff 0f 83 da ad fb ff c3 66 0f 1f 84 00 00 00 00 00
RSP: 002b:00007ffd7dd4f8b8 EFLAGS: 00000293 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffd7dd4f910 RCX: 0000000000446d1a RDX:
0000000020000000 RSI: 0000000020000100 RDI: 00007ffd7dd4f8d0 RBP:
00007ffd7dd4f8d0 R08: 00007ffd7dd4f910 R09: 00007ffd00000015 R10:
0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13:
0000000000000004 R14: 0000000000000003 R15: 0000000000000003
Allocated by task 3913: kasan_save_stack mm/kasan/common.c:48 [inline]
kasan_set_track mm/kasan/common.c:56 [inline]
__kasan_kmalloc+0x100/0x130 mm/kasan/common.c:461 kmalloc_node
include/linux/slab.h:577 [inline] __vmalloc_area_node mm/vmalloc.c:2429
[inline] __vmalloc_node_range+0x2c7/0x870 mm/vmalloc.c:2511
module_alloc+0x7e/0x90 arch/x86/kernel/module.c:75
bpf_jit_binary_alloc+0x123/0x230 kernel/bpf/core.c:871
bpf_int_jit_compile+0x7995/0x8920 arch/x86/net/bpf_jit_comp.c:1911
bpf_prog_select_runtime+0x76d/0xa60 kernel/bpf/core.c:1807
bpf_migrate_filter net/core/filter.c:1290 [inline]
bpf_prepare_filter+0xec2/0x1140 net/core/filter.c:1338
bpf_prog_create_from_user+0x2ad/0x3e0 net/core/filter.c:1432
seccomp_prepare_filter kernel/seccomp.c:567 [inline]
seccomp_prepare_user_filter kernel/seccomp.c:604 [inline]
seccomp_set_mode_filter kernel/seccomp.c:1546 [inline]
do_seccomp+0x852/0x20b0 kernel/seccomp.c:1661 do_syscall_64+0x31/0x70
arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9
The buggy address belongs to the object at ffff8880a9684b80 which
belongs to the cache kmalloc-32 of size 32 The buggy address is located
24 bytes inside of 32-byte region [ffff8880a9684b80, ffff8880a9684ba0)
The buggy address belongs to the page: page:00000000f697ca3d refcount:1
mapcount:0 mapping:0000000000000000 index:0xffff8880a9684fc1 pfn:0xa9684
flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002a5d5c8
ffffea0002a98588 ffff8880aa440100 raw: ffff8880a9684fc1 ffff8880a9684000
000000010000003f 0000000000000000 page dumped because: kasan: bad access
detected
Memory state around the buggy address: ffff8880a9684a80: fa fb fb fb fc
fc fc fc fa fb fb fb fc fc fc fc ffff8880a9684b00: 00 fc fc fc fc fc fc
fc fa fb fb fb fc fc fc fc >ffff8880a9684b80: 00 fc fc fc fc fc fc fc fa
fb fb fb fc fc fc fc ^ ffff8880a9684c00: fa fb fb fb fc fc fc fc fa fb
fb fb fc fc fc fc ffff8880a9684c80: 00 00 01 fc fc fc fc fc fa fb fb fb
fc fc fc fc
==================================================================
--- This report is generated by a bot. It may contain errors. See
https://goo.gl/tpsmEJ for more information about syzbot. syzbot
engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status
for how to communicate with syzbot. syzbot can test patches for this
issue, for details see: https://goo.gl/tpsmEJ#testing-patches
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [syzbot] KASAN: slab-out-of-bounds Read in squashfs_get_id
2020-09-25 14:48 KASAN: slab-out-of-bounds Read in squashfs_get_id syzbot
2020-10-14 7:52 ` Fox Chen
@ 2021-03-11 11:23 ` syzbot
2021-03-11 15:04 ` Dmitry Vyukov
1 sibling, 1 reply; 4+ messages in thread
From: syzbot @ 2021-03-11 11:23 UTC (permalink / raw)
To: akpm, foxhlchen, gregkh, linux-kernel, phillip, syzkaller-bugs, torvalds
syzbot suspects this issue was fixed by commit:
commit e812cbbbbbb15adbbbee176baa1e8bda53059bf0
Author: Phillip Lougher <phillip@squashfs.org.uk>
Date: Tue Feb 9 21:41:50 2021 +0000
squashfs: avoid out of bounds writes in decompressors
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11bfa48ad00000
start commit: cd796ed3 Merge tag 'trace-v5.10-rc7' of git://git.kernel.o..
git tree: upstream
kernel config: https://syzkaller.appspot.com/x/.config?x=59df2a4dced5f928
dashboard link: https://syzkaller.appspot.com/bug?extid=8e28bba73ed1772a6802
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1138f80f500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=125e080f500000
If the result looks correct, please mark the issue as fixed by replying with:
#syz fix: squashfs: avoid out of bounds writes in decompressors
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [syzbot] KASAN: slab-out-of-bounds Read in squashfs_get_id
2021-03-11 11:23 ` [syzbot] " syzbot
@ 2021-03-11 15:04 ` Dmitry Vyukov
0 siblings, 0 replies; 4+ messages in thread
From: Dmitry Vyukov @ 2021-03-11 15:04 UTC (permalink / raw)
To: syzbot
Cc: Andrew Morton, Fox Chen, Greg Kroah-Hartman, LKML, phillip,
syzkaller-bugs, Linus Torvalds
On Thu, Mar 11, 2021 at 12:23 PM syzbot
<syzbot+8e28bba73ed1772a6802@syzkaller.appspotmail.com> wrote:
>
> syzbot suspects this issue was fixed by commit:
>
> commit e812cbbbbbb15adbbbee176baa1e8bda53059bf0
> Author: Phillip Lougher <phillip@squashfs.org.uk>
> Date: Tue Feb 9 21:41:50 2021 +0000
>
> squashfs: avoid out of bounds writes in decompressors
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=11bfa48ad00000
> start commit: cd796ed3 Merge tag 'trace-v5.10-rc7' of git://git.kernel.o..
> git tree: upstream
> kernel config: https://syzkaller.appspot.com/x/.config?x=59df2a4dced5f928
> dashboard link: https://syzkaller.appspot.com/bug?extid=8e28bba73ed1772a6802
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1138f80f500000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=125e080f500000
>
> If the result looks correct, please mark the issue as fixed by replying with:
>
> #syz fix: squashfs: avoid out of bounds writes in decompressors
>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
Looks reasonable:
#syz fix: squashfs: avoid out of bounds writes in decompressors
^ permalink raw reply [flat|nested] 4+ messages in thread
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2020-09-25 14:48 KASAN: slab-out-of-bounds Read in squashfs_get_id syzbot
2020-10-14 7:52 ` Fox Chen
2021-03-11 11:23 ` [syzbot] " syzbot
2021-03-11 15:04 ` Dmitry Vyukov
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