In the Linux kernel, the following vulnerability has been resolved:
i2c: ismt: Fix an out-of-bounds bug in ismt_access()
When the driver does not check the data from the user, the variable
'data->block[0]' may be very large to cause an out-of-bounds bug.
The following log can reveal it:
[ 33.995542] i2c i2c-1: ioctl, cmd=0x720, arg=0x7ffcb3dc3a20
[ 33.995978] ismt_smbus 0000:00:05.0: I2C_SMBUS_BLOCK_DATA: WRITE
[ 33.996475] ==================================================================
[ 33.996995] BUG: KASAN: out-of-bounds in ismt_access.cold+0x374/0x214b
[ 33.997473] Read of size 18446744073709551615 at addr ffff88810efcfdb1 by task ismt_poc/485
[ 33.999450] Call Trace:
[ 34.001849] memcpy+0x20/0x60
[ 34.002077] ismt_access.cold+0x374/0x214b
[ 34.003382] __i2c_smbus_xfer+0x44f/0xfb0
[ 34.004007] i2c_smbus_xfer+0x10a/0x390
[ 34.004291] i2cdev_ioctl_smbus+0x2c8/0x710
[ 34.005196] i2cdev_ioctl+0x5ec/0x74c
Fix this bug by checking the size of 'data->block[0]' first.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: Fix user-after-free
This uses l2cap_chan_hold_unless_zero() after calling
__l2cap_get_chan_blah() to prevent the following trace:
Bluetooth: l2cap_core.c:static void l2cap_chan_destroy(struct kref
*kref)
Bluetooth: chan 0000000023c4974d
Bluetooth: parent 00000000ae861c08
==================================================================
BUG: KASAN: use-after-free in __mutex_waiter_is_first
kernel/locking/mutex.c:191 [inline]
BUG: KASAN: use-after-free in __mutex_lock_common
kernel/locking/mutex.c:671 [inline]
BUG: KASAN: use-after-free in __mutex_lock+0x278/0x400
kernel/locking/mutex.c:729
Read of size 8 at addr ffff888006a49b08 by task kworker/u3:2/389
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix race between quota enable and quota rescan ioctl
When enabling quotas, at btrfs_quota_enable(), after committing the
transaction, we change fs_info->quota_root to point to the quota root we
created and set BTRFS_FS_QUOTA_ENABLED at fs_info->flags. Then we try
to start the qgroup rescan worker, first by initializing it with a call
to qgroup_rescan_init() - however if that fails we end up freeing the
quota root but we leave fs_info->quota_root still pointing to it, this
can later result in a use-after-free somewhere else.
We have previously set the flags BTRFS_FS_QUOTA_ENABLED and
BTRFS_QGROUP_STATUS_FLAG_ON, so we can only fail with -EINPROGRESS at
btrfs_quota_enable(), which is possible if someone already called the
quota rescan ioctl, and therefore started the rescan worker.
So fix this by ignoring an -EINPROGRESS and asserting we can't get any
other error.
In the Linux kernel, the following vulnerability has been resolved:
md: fix a crash in mempool_free
There's a crash in mempool_free when running the lvm test
shell/lvchange-rebuild-raid.sh.
The reason for the crash is this:
* super_written calls atomic_dec_and_test(&mddev->pending_writes) and
wake_up(&mddev->sb_wait). Then it calls rdev_dec_pending(rdev, mddev)
and bio_put(bio).
* so, the process that waited on sb_wait and that is woken up is racing
with bio_put(bio).
* if the process wins the race, it calls bioset_exit before bio_put(bio)
is executed.
* bio_put(bio) attempts to free a bio into a destroyed bio set - causing
a crash in mempool_free.
We fix this bug by moving bio_put before atomic_dec_and_test.
We also move rdev_dec_pending before atomic_dec_and_test as suggested by
Neil Brown.
The function md_end_flush has a similar bug - we must call bio_put before
we decrement the number of in-progress bios.
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 11557f0067 P4D 11557f0067 PUD 0
Oops: 0002 [#1] PREEMPT SMP
CPU: 0 PID: 73 Comm: kworker/0:1 Not tainted 6.1.0-rc3 #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
Workqueue: kdelayd flush_expired_bios [dm_delay]
RIP: 0010:mempool_free+0x47/0x80
Code: 48 89 ef 5b 5d ff e0 f3 c3 48 89 f7 e8 32 45 3f 00 48 63 53 08 48 89 c6 3b 53 04 7d 2d 48 8b 43 10 8d 4a 01 48 89 df 89 4b 08 <48> 89 2c d0 e8 b0 45 3f 00 48 8d 7b 30 5b 5d 31 c9 ba 01 00 00 00
RSP: 0018:ffff88910036bda8 EFLAGS: 00010093
RAX: 0000000000000000 RBX: ffff8891037b65d8 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000202 RDI: ffff8891037b65d8
RBP: ffff8891447ba240 R08: 0000000000012908 R09: 00000000003d0900
R10: 0000000000000000 R11: 0000000000173544 R12: ffff889101a14000
R13: ffff8891562ac300 R14: ffff889102b41440 R15: ffffe8ffffa00d05
FS: 0000000000000000(0000) GS:ffff88942fa00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000001102e99000 CR4: 00000000000006b0
Call Trace:
<TASK>
clone_endio+0xf4/0x1c0 [dm_mod]
clone_endio+0xf4/0x1c0 [dm_mod]
__submit_bio+0x76/0x120
submit_bio_noacct_nocheck+0xb6/0x2a0
flush_expired_bios+0x28/0x2f [dm_delay]
process_one_work+0x1b4/0x300
worker_thread+0x45/0x3e0
? rescuer_thread+0x380/0x380
kthread+0xc2/0x100
? kthread_complete_and_exit+0x20/0x20
ret_from_fork+0x1f/0x30
</TASK>
Modules linked in: brd dm_delay dm_raid dm_mod af_packet uvesafb cfbfillrect cfbimgblt cn cfbcopyarea fb font fbdev tun autofs4 binfmt_misc configfs ipv6 virtio_rng virtio_balloon rng_core virtio_net pcspkr net_failover failover qemu_fw_cfg button mousedev raid10 raid456 libcrc32c async_raid6_recov async_memcpy async_pq raid6_pq async_xor xor async_tx raid1 raid0 md_mod sd_mod t10_pi crc64_rocksoft crc64 virtio_scsi scsi_mod evdev psmouse bsg scsi_common [last unloaded: brd]
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
In the Linux kernel, the following vulnerability has been resolved:
tracing: Fix race issue between cpu buffer write and swap
Warning happened in rb_end_commit() at code:
if (RB_WARN_ON(cpu_buffer, !local_read(&cpu_buffer->committing)))
WARNING: CPU: 0 PID: 139 at kernel/trace/ring_buffer.c:3142
rb_commit+0x402/0x4a0
Call Trace:
ring_buffer_unlock_commit+0x42/0x250
trace_buffer_unlock_commit_regs+0x3b/0x250
trace_event_buffer_commit+0xe5/0x440
trace_event_buffer_reserve+0x11c/0x150
trace_event_raw_event_sched_switch+0x23c/0x2c0
__traceiter_sched_switch+0x59/0x80
__schedule+0x72b/0x1580
schedule+0x92/0x120
worker_thread+0xa0/0x6f0
It is because the race between writing event into cpu buffer and swapping
cpu buffer through file per_cpu/cpu0/snapshot:
Write on CPU 0 Swap buffer by per_cpu/cpu0/snapshot on CPU 1
-------- --------
tracing_snapshot_write()
[...]
ring_buffer_lock_reserve()
cpu_buffer = buffer->buffers[cpu]; // 1. Suppose find 'cpu_buffer_a';
[...]
rb_reserve_next_event()
[...]
ring_buffer_swap_cpu()
if (local_read(&cpu_buffer_a->committing))
goto out_dec;
if (local_read(&cpu_buffer_b->committing))
goto out_dec;
buffer_a->buffers[cpu] = cpu_buffer_b;
buffer_b->buffers[cpu] = cpu_buffer_a;
// 2. cpu_buffer has swapped here.
rb_start_commit(cpu_buffer);
if (unlikely(READ_ONCE(cpu_buffer->buffer)
!= buffer)) { // 3. This check passed due to 'cpu_buffer->buffer'
[...] // has not changed here.
return NULL;
}
cpu_buffer_b->buffer = buffer_a;
cpu_buffer_a->buffer = buffer_b;
[...]
// 4. Reserve event from 'cpu_buffer_a'.
ring_buffer_unlock_commit()
[...]
cpu_buffer = buffer->buffers[cpu]; // 5. Now find 'cpu_buffer_b' !!!
rb_commit(cpu_buffer)
rb_end_commit() // 6. WARN for the wrong 'committing' state !!!
Based on above analysis, we can easily reproduce by following testcase:
``` bash
#!/bin/bash
dmesg -n 7
sysctl -w kernel.panic_on_warn=1
TR=/sys/kernel/tracing
echo 7 > ${TR}/buffer_size_kb
echo "sched:sched_switch" > ${TR}/set_event
while [ true ]; do
echo 1 > ${TR}/per_cpu/cpu0/snapshot
done &
while [ true ]; do
echo 1 > ${TR}/per_cpu/cpu0/snapshot
done &
while [ true ]; do
echo 1 > ${TR}/per_cpu/cpu0/snapshot
done &
```
To fix it, IIUC, we can use smp_call_function_single() to do the swap on
the target cpu where the buffer is located, so that above race would be
avoided.
In the Linux kernel, the following vulnerability has been resolved:
USB: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic at
once.
In the Linux kernel, the following vulnerability has been resolved:
ip6mr: Fix skb_under_panic in ip6mr_cache_report()
skbuff: skb_under_panic: text:ffffffff88771f69 len:56 put:-4
head:ffff88805f86a800 data:ffff887f5f86a850 tail:0x88 end:0x2c0 dev:pim6reg
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:192!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 2 PID: 22968 Comm: kworker/2:11 Not tainted 6.5.0-rc3-00044-g0a8db05b571a #236
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:skb_panic+0x152/0x1d0
Call Trace:
<TASK>
skb_push+0xc4/0xe0
ip6mr_cache_report+0xd69/0x19b0
reg_vif_xmit+0x406/0x690
dev_hard_start_xmit+0x17e/0x6e0
__dev_queue_xmit+0x2d6a/0x3d20
vlan_dev_hard_start_xmit+0x3ab/0x5c0
dev_hard_start_xmit+0x17e/0x6e0
__dev_queue_xmit+0x2d6a/0x3d20
neigh_connected_output+0x3ed/0x570
ip6_finish_output2+0x5b5/0x1950
ip6_finish_output+0x693/0x11c0
ip6_output+0x24b/0x880
NF_HOOK.constprop.0+0xfd/0x530
ndisc_send_skb+0x9db/0x1400
ndisc_send_rs+0x12a/0x6c0
addrconf_dad_completed+0x3c9/0xea0
addrconf_dad_work+0x849/0x1420
process_one_work+0xa22/0x16e0
worker_thread+0x679/0x10c0
ret_from_fork+0x28/0x60
ret_from_fork_asm+0x11/0x20
When setup a vlan device on dev pim6reg, DAD ns packet may sent on reg_vif_xmit().
reg_vif_xmit()
ip6mr_cache_report()
skb_push(skb, -skb_network_offset(pkt));//skb_network_offset(pkt) is 4
And skb_push declared as:
void *skb_push(struct sk_buff *skb, unsigned int len);
skb->data -= len;
//0xffff88805f86a84c - 0xfffffffc = 0xffff887f5f86a850
skb->data is set to 0xffff887f5f86a850, which is invalid mem addr, lead to skb_push() fails.
In the Linux kernel, the following vulnerability has been resolved:
md/raid10: check slab-out-of-bounds in md_bitmap_get_counter
If we write a large number to md/bitmap_set_bits, md_bitmap_checkpage()
will return -EINVAL because 'page >= bitmap->pages', but the return value
was not checked immediately in md_bitmap_get_counter() in order to set
*blocks value and slab-out-of-bounds occurs.
Move check of 'page >= bitmap->pages' to md_bitmap_get_counter() and
return directly if true.
In the Linux kernel, the following vulnerability has been resolved:
kernel/fail_function: fix memory leak with using debugfs_lookup()
When calling debugfs_lookup() the result must have dput() called on it,
otherwise the memory will leak over time. To make things simpler, just
call debugfs_lookup_and_remove() instead which handles all of the logic
at once.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix BUG_ON condition in btrfs_cancel_balance
Pausing and canceling balance can race to interrupt balance lead to BUG_ON
panic in btrfs_cancel_balance. The BUG_ON condition in btrfs_cancel_balance
does not take this race scenario into account.
However, the race condition has no other side effects. We can fix that.
Reproducing it with panic trace like this:
kernel BUG at fs/btrfs/volumes.c:4618!
RIP: 0010:btrfs_cancel_balance+0x5cf/0x6a0
Call Trace:
<TASK>
? do_nanosleep+0x60/0x120
? hrtimer_nanosleep+0xb7/0x1a0
? sched_core_clone_cookie+0x70/0x70
btrfs_ioctl_balance_ctl+0x55/0x70
btrfs_ioctl+0xa46/0xd20
__x64_sys_ioctl+0x7d/0xa0
do_syscall_64+0x38/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Race scenario as follows:
> mutex_unlock(&fs_info->balance_mutex);
> --------------------
> .......issue pause and cancel req in another thread
> --------------------
> ret = __btrfs_balance(fs_info);
>
> mutex_lock(&fs_info->balance_mutex);
> if (ret == -ECANCELED && atomic_read(&fs_info->balance_pause_req)) {
> btrfs_info(fs_info, "balance: paused");
> btrfs_exclop_balance(fs_info, BTRFS_EXCLOP_BALANCE_PAUSED);
> }