KASAN: slab-out-of-bounds Write in extAlloc

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14b0db38880000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=6837936371bae0b19893
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/98c0bdb4abb3/disk-3f8a27f9.raw.xz
vmlinux: https://storage.googleapis.com/ea228ff02669/vmlinux-3f8a27f9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+683793...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-out-of-bounds in atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
BUG: KASAN: slab-out-of-bounds in extBalloc fs/jfs/jfs_extent.c:557 [inline]
BUG: KASAN: slab-out-of-bounds in extAlloc+0xb8e/0xdb0 fs/jfs/jfs_extent.c:138
Write of size 4 at addr ffff88804f7f5218 by task syz-executor.4/23774

CPU: 0 PID: 23774 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
kasan_report+0x8f/0xa0 mm/kasan/report.c:412
atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
extBalloc fs/jfs/jfs_extent.c:557 [inline]
extAlloc+0xb8e/0xdb0 fs/jfs/jfs_extent.c:138
jfs_get_block+0x1f5/0xae0 fs/jfs/inode.c:258
nobh_write_begin+0x446/0x1030 fs/buffer.c:2619
jfs_write_begin+0x3e/0x1a0 fs/jfs/inode.c:323
generic_perform_write+0x1f8/0x4d0 mm/filemap.c:3170
__generic_file_write_iter+0x24b/0x610 mm/filemap.c:3295
generic_file_write_iter+0x3f8/0x730 mm/filemap.c:3323
call_write_iter include/linux/fs.h:1821 [inline]
new_sync_write fs/read_write.c:474 [inline]
__vfs_write+0x51b/0x770 fs/read_write.c:487
vfs_write+0x1f3/0x540 fs/read_write.c:549
ksys_write+0x12b/0x2a0 fs/read_write.c:599
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f258f3ed5a9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f258dd1f168 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f258f50f120 RCX: 00007f258f3ed5a9
RDX: 000000000208e24b RSI: 0000000020000480 RDI: 0000000000000007
RBP: 00007f258f448560 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff1ad13aff R14: 00007f258dd1f300 R15: 0000000000022000

Allocated by task 23765:
kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625
kmalloc include/linux/slab.h:515 [inline]
dbMount+0x4d/0x880 fs/jfs/jfs_dmap.c:176
jfs_mount+0x124/0x3d0 fs/jfs/jfs_mount.c:133
jfs_fill_super+0x55c/0xb50 fs/jfs/super.c:589
mount_bdev+0x2fc/0x3b0 fs/super.c:1158
mount_fs+0xa3/0x310 fs/super.c:1261
vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
vfs_kern_mount fs/namespace.c:951 [inline]
do_new_mount fs/namespace.c:2492 [inline]
do_mount+0x115c/0x2f50 fs/namespace.c:2822
ksys_mount+0xcf/0x130 fs/namespace.c:3038
__do_sys_mount fs/namespace.c:3052 [inline]
__se_sys_mount fs/namespace.c:3049 [inline]
__x64_sys_mount+0xba/0x150 fs/namespace.c:3049
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 8083:
__cache_free mm/slab.c:3503 [inline]
kfree+0xcc/0x210 mm/slab.c:3822
skb_free_head net/core/skbuff.c:563 [inline]
skb_release_data+0x6de/0x920 net/core/skbuff.c:583
skb_release_all net/core/skbuff.c:640 [inline]
__kfree_skb+0x46/0x60 net/core/skbuff.c:654
sk_wmem_free_skb include/net/sock.h:1468 [inline]
tcp_rtx_queue_unlink_and_free include/net/tcp.h:1769 [inline]
tcp_clean_rtx_queue net/ipv4/tcp_input.c:3160 [inline]
tcp_ack+0x1d1e/0x51d0 net/ipv4/tcp_input.c:3695
tcp_rcv_established+0x66b/0x1ef0 net/ipv4/tcp_input.c:5670
tcp_v4_do_rcv+0x5d6/0x870 net/ipv4/tcp_ipv4.c:1547
sk_backlog_rcv include/net/sock.h:952 [inline]
__release_sock+0x134/0x3a0 net/core/sock.c:2362
release_sock+0x54/0x1b0 net/core/sock.c:2901
tcp_sendmsg+0x36/0x40 net/ipv4/tcp.c:1463
inet_sendmsg+0x132/0x5a0 net/ipv4/af_inet.c:798
sock_sendmsg_nosec net/socket.c:651 [inline]
sock_sendmsg+0xc3/0x120 net/socket.c:661
sock_write_iter+0x287/0x3c0 net/socket.c:966
call_write_iter include/linux/fs.h:1821 [inline]
new_sync_write fs/read_write.c:474 [inline]
__vfs_write+0x51b/0x770 fs/read_write.c:487
vfs_write+0x1f3/0x540 fs/read_write.c:549
ksys_write+0x12b/0x2a0 fs/read_write.c:599
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88804f7f4b40
which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 1752 bytes inside of
2048-byte region [ffff88804f7f4b40, ffff88804f7f5340)
The buggy address belongs to the page:
page:ffffea00013dfd00 count:1 mapcount:0 mapping:ffff88813bff0c40 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffffea00014d0f88 ffffea00012bad88 ffff88813bff0c40
raw: 0000000000000000 ffff88804f7f42c0 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88804f7f5100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88804f7f5180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88804f7f5200: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff88804f7f5280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88804f7f5300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
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[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y

console output: https://syzkaller.appspot.com/x/log.txt?x=17b7a19c880000

kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=6837936371bae0b19893
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1035f19c880000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17ff359c880000

Downloadable assets:
disk image: https://storage.googleapis.com/98c0bdb4abb3/disk-3f8a27f9.raw.xz
vmlinux: https://storage.googleapis.com/ea228ff02669/vmlinux-3f8a27f9.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+683793...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-out-of-bounds in atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
BUG: KASAN: slab-out-of-bounds in extBalloc fs/jfs/jfs_extent.c:557 [inline]
BUG: KASAN: slab-out-of-bounds in extAlloc+0xb8e/0xdb0 fs/jfs/jfs_extent.c:138

Write of size 4 at addr ffff8880b2d61a18 by task syz-executor237/8076

CPU: 0 PID: 8076 Comm: syz-executor237 Not tainted 4.19.211-syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
kasan_report+0x8f/0xa0 mm/kasan/report.c:412
atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
extBalloc fs/jfs/jfs_extent.c:557 [inline]
extAlloc+0xb8e/0xdb0 fs/jfs/jfs_extent.c:138
jfs_get_block+0x1f5/0xae0 fs/jfs/inode.c:258
nobh_write_begin+0x446/0x1030 fs/buffer.c:2619
jfs_write_begin+0x3e/0x1a0 fs/jfs/inode.c:323
generic_perform_write+0x1f8/0x4d0 mm/filemap.c:3170
__generic_file_write_iter+0x24b/0x610 mm/filemap.c:3295
generic_file_write_iter+0x3f8/0x730 mm/filemap.c:3323
call_write_iter include/linux/fs.h:1821 [inline]
new_sync_write fs/read_write.c:474 [inline]
__vfs_write+0x51b/0x770 fs/read_write.c:487
vfs_write+0x1f3/0x540 fs/read_write.c:549
ksys_write+0x12b/0x2a0 fs/read_write.c:599
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

RIP: 0033:0x7fa7ba642e39
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff63f7c418 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa7ba642e39
RDX: 000000000208e24b RSI: 0000000020000480 RDI: 0000000000000003
RBP: 00007fa7ba6026a0 R08: 0000000000000000 R09: 00007fa7ba6026a0
R10: 00005555556912c0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00080000000000f8 R15: 0000000000000000

Allocated by task 8076:

kmem_cache_alloc_trace+0x12f/0x380 mm/slab.c:3625
kmalloc include/linux/slab.h:515 [inline]
dbMount+0x4d/0x880 fs/jfs/jfs_dmap.c:176
jfs_mount+0x124/0x3d0 fs/jfs/jfs_mount.c:133
jfs_fill_super+0x55c/0xb50 fs/jfs/super.c:589
mount_bdev+0x2fc/0x3b0 fs/super.c:1158
mount_fs+0xa3/0x310 fs/super.c:1261
vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
vfs_kern_mount fs/namespace.c:951 [inline]
do_new_mount fs/namespace.c:2492 [inline]
do_mount+0x115c/0x2f50 fs/namespace.c:2822
ksys_mount+0xcf/0x130 fs/namespace.c:3038
__do_sys_mount fs/namespace.c:3052 [inline]
__se_sys_mount fs/namespace.c:3049 [inline]
__x64_sys_mount+0xba/0x150 fs/namespace.c:3049
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8880b2d61340

which belongs to the cache kmalloc-2048 of size 2048
The buggy address is located 1752 bytes inside of

2048-byte region [ffff8880b2d61340, ffff8880b2d61b40)

The buggy address belongs to the page:

page:ffffea0002cb5800 count:1 mapcount:0 mapping:ffff88813bff0c40 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffffea0002651b08 ffff88813bff1948 ffff88813bff0c40
raw: 0000000000000000 ffff8880b2d60240 0000000100000003 0000000000000000

page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff8880b2d61900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8880b2d61980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880b2d61a00: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff8880b2d61a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8880b2d61b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================