In the Linux kernel, the following vulnerability has been resolved:
ALSA: ac97: Fix possible NULL dereference in snd_ac97_mixer
smatch error:
sound/pci/ac97/ac97_codec.c:2354 snd_ac97_mixer() error:
we previously assumed 'rac97' could be null (see line 2072)
remove redundant assignment, return error if rac97 is NULL.
In the Linux kernel, the following vulnerability has been resolved:
fbdev: omapfb: lcd_mipid: Fix an error handling path in mipid_spi_probe()
If 'mipid_detect()' fails, we must free 'md' to avoid a memory leak.
In the Linux kernel, the following vulnerability has been resolved:
Input: exc3000 - properly stop timer on shutdown
We need to stop the timer on driver unbind or probe failures, otherwise
we get UAF/Oops.
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath6kl: reduce WARN to dev_dbg() in callback
The warn is triggered on a known race condition, documented in the code above
the test, that is correctly handled. Using WARN() hinders automated testing.
Reducing severity.
In the Linux kernel, the following vulnerability has been resolved:
wifi: ath9k: hif_usb: fix memory leak of remain_skbs
hif_dev->remain_skb is allocated and used exclusively in
ath9k_hif_usb_rx_stream(). It is implied that an allocated remain_skb is
processed and subsequently freed (in error paths) only during the next
call of ath9k_hif_usb_rx_stream().
So, if the urbs are deallocated between those two calls due to the device
deinitialization or suspend, it is possible that ath9k_hif_usb_rx_stream()
is not called next time and the allocated remain_skb is leaked. Our local
Syzkaller instance was able to trigger that.
remain_skb makes sense when receiving two consecutive urbs which are
logically linked together, i.e. a specific data field from the first skb
indicates a cached skb to be allocated, memcpy'd with some data and
subsequently processed in the next call to ath9k_hif_usb_rx_stream(). Urbs
deallocation supposedly makes that link irrelevant so we need to free the
cached skb in those cases.
Fix the leak by introducing a function to explicitly free remain_skb (if
it is not NULL) when the rx urbs have been deallocated. remain_skb is NULL
when it has not been allocated at all (hif_dev struct is kzalloced) or
when it has been processed in next call to ath9k_hif_usb_rx_stream().
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: conntrack: fix wrong ct->timeout value
(struct nf_conn)->timeout is an interval before the conntrack
confirmed. After confirmed, it becomes a timestamp.
It is observed that timeout of an unconfirmed conntrack:
- Set by calling ctnetlink_change_timeout(). As a result,
`nfct_time_stamp` was wrongly added to `ct->timeout` twice.
- Get by calling ctnetlink_dump_timeout(). As a result,
`nfct_time_stamp` was wrongly subtracted.
Call Trace:
<TASK>
dump_stack_lvl
ctnetlink_dump_timeout
__ctnetlink_glue_build
ctnetlink_glue_build
__nfqnl_enqueue_packet
nf_queue
nf_hook_slow
ip_mc_output
? __pfx_ip_finish_output
ip_send_skb
? __pfx_dst_output
udp_send_skb
udp_sendmsg
? __pfx_ip_generic_getfrag
sock_sendmsg
Separate the 2 cases in:
- Setting `ct->timeout` in __nf_ct_set_timeout().
- Getting `ct->timeout` in ctnetlink_dump_timeout().
Pablo appends:
Update ctnetlink to set up the timeout _after_ the IPS_CONFIRMED flag is
set on, otherwise conntrack creation via ctnetlink breaks.
Note that the problem described in this patch occurs since the
introduction of the nfnetlink_queue conntrack support, select a
sufficiently old Fixes: tag for -stable kernel to pick up this fix.
In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_fq: fix integer overflow of "credit"
if sch_fq is configured with "initial quantum" having values greater than
INT_MAX, the first assignment of "credit" does signed integer overflow to
a very negative value.
In this situation, the syzkaller script provided by Cristoph triggers the
CPU soft-lockup warning even with few sockets. It's not an infinite loop,
but "credit" wasn't probably meant to be minus 2Gb for each new flow.
Capping "initial quantum" to INT_MAX proved to fix the issue.
v2: validation of "initial quantum" is done in fq_policy, instead of open
coding in fq_change() _ suggested by Jakub Kicinski
In the Linux kernel, the following vulnerability has been resolved:
btrfs: reject invalid reloc tree root keys with stack dump
[BUG]
Syzbot reported a crash that an ASSERT() got triggered inside
prepare_to_merge().
That ASSERT() makes sure the reloc tree is properly pointed back by its
subvolume tree.
[CAUSE]
After more debugging output, it turns out we had an invalid reloc tree:
BTRFS error (device loop1): reloc tree mismatch, root 8 has no reloc root, expect reloc root key (-8, 132, 8) gen 17
Note the above root key is (TREE_RELOC_OBJECTID, ROOT_ITEM,
QUOTA_TREE_OBJECTID), meaning it's a reloc tree for quota tree.
But reloc trees can only exist for subvolumes, as for non-subvolume
trees, we just COW the involved tree block, no need to create a reloc
tree since those tree blocks won't be shared with other trees.
Only subvolumes tree can share tree blocks with other trees (thus they
have BTRFS_ROOT_SHAREABLE flag).
Thus this new debug output proves my previous assumption that corrupted
on-disk data can trigger that ASSERT().
[FIX]
Besides the dedicated fix and the graceful exit, also let tree-checker to
check such root keys, to make sure reloc trees can only exist for subvolumes.