In the Linux kernel, the following vulnerability has been resolved:
can: pch_can: pch_can_rx_normal: fix use after free
After calling netif_receive_skb(skb), dereferencing skb is unsafe.
Especially, the can_frame cf which aliases skb memory is dereferenced
just after the call netif_receive_skb(skb).
Reordering the lines solves the issue.
In the Linux kernel, the following vulnerability has been resolved:
can: sja1000: fix use after free in ems_pcmcia_add_card()
If the last channel is not available then "dev" is freed. Fortunately,
we can just use "pdev->irq" instead.
Also we should check if at least one channel was set up.
In the Linux kernel, the following vulnerability has been resolved:
HID: bigbenff: prevent null pointer dereference
When emulating the device through uhid, there is a chance we don't have
output reports and so report_field is null.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: pcm: oss: Fix negative period/buffer sizes
The period size calculation in OSS layer may receive a negative value
as an error, but the code there assumes only the positive values and
handle them with size_t. Due to that, a too big value may be passed
to the lower layers.
This patch changes the code to handle with ssize_t and adds the proper
error checks appropriately.
In the Linux kernel, the following vulnerability has been resolved:
nfsd: fix use-after-free due to delegation race
A delegation break could arrive as soon as we've called vfs_setlease. A
delegation break runs a callback which immediately (in
nfsd4_cb_recall_prepare) adds the delegation to del_recall_lru. If we
then exit nfs4_set_delegation without hashing the delegation, it will be
freed as soon as the callback is done with it, without ever being
removed from del_recall_lru.
Symptoms show up later as use-after-free or list corruption warnings,
usually in the laundromat thread.
I suspect aba2072f4523 "nfsd: grant read delegations to clients holding
writes" made this bug easier to hit, but I looked as far back as v3.0
and it looks to me it already had the same problem. So I'm not sure
where the bug was introduced; it may have been there from the beginning.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: free exchange changeset on failures
Fstests runs on my VMs have show several kmemleak reports like the following.
unreferenced object 0xffff88811ae59080 (size 64):
comm "xfs_io", pid 12124, jiffies 4294987392 (age 6.368s)
hex dump (first 32 bytes):
00 c0 1c 00 00 00 00 00 ff cf 1c 00 00 00 00 00 ................
90 97 e5 1a 81 88 ff ff 90 97 e5 1a 81 88 ff ff ................
backtrace:
[<00000000ac0176d2>] ulist_add_merge+0x60/0x150 [btrfs]
[<0000000076e9f312>] set_state_bits+0x86/0xc0 [btrfs]
[<0000000014fe73d6>] set_extent_bit+0x270/0x690 [btrfs]
[<000000004f675208>] set_record_extent_bits+0x19/0x20 [btrfs]
[<00000000b96137b1>] qgroup_reserve_data+0x274/0x310 [btrfs]
[<0000000057e9dcbb>] btrfs_check_data_free_space+0x5c/0xa0 [btrfs]
[<0000000019c4511d>] btrfs_delalloc_reserve_space+0x1b/0xa0 [btrfs]
[<000000006d37e007>] btrfs_dio_iomap_begin+0x415/0x970 [btrfs]
[<00000000fb8a74b8>] iomap_iter+0x161/0x1e0
[<0000000071dff6ff>] __iomap_dio_rw+0x1df/0x700
[<000000002567ba53>] iomap_dio_rw+0x5/0x20
[<0000000072e555f8>] btrfs_file_write_iter+0x290/0x530 [btrfs]
[<000000005eb3d845>] new_sync_write+0x106/0x180
[<000000003fb505bf>] vfs_write+0x24d/0x2f0
[<000000009bb57d37>] __x64_sys_pwrite64+0x69/0xa0
[<000000003eba3fdf>] do_syscall_64+0x43/0x90
In case brtfs_qgroup_reserve_data() or btrfs_delalloc_reserve_metadata()
fail the allocated extent_changeset will not be freed.
So in btrfs_check_data_free_space() and btrfs_delalloc_reserve_space()
free the allocated extent_changeset to get rid of the allocated memory.
The issue currently only happens in the direct IO write path, but only
after 65b3c08606e5 ("btrfs: fix ENOSPC failure when attempting direct IO
write into NOCOW range"), and also at defrag_one_locked_target(). Every
other place is always calling extent_changeset_free() even if its call
to btrfs_delalloc_reserve_space() or btrfs_check_data_free_space() has
failed.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: pcm: oss: Limit the period size to 16MB
Set the practical limit to the period size (the fragment shift in OSS)
instead of a full 31bit; a too large value could lead to the exhaust
of memory as we allocate temporary buffers of the period size, too.
As of this patch, we set to 16MB limit, which should cover all use
cases.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: Fix slab-use-after-free in l2cap_connect()
Extend a critical section to prevent chan from early freeing.
Also make the l2cap_connect() return type void. Nothing is using the
returned value but it is ugly to return a potentially freed pointer.
Making it void will help with backports because earlier kernels did use
the return value. Now the compile will break for kernels where this
patch is not a complete fix.
Call stack summary:
[use]
l2cap_bredr_sig_cmd
l2cap_connect
┌ mutex_lock(&conn->chan_lock);
│ chan = pchan->ops->new_connection(pchan); <- alloc chan
│ __l2cap_chan_add(conn, chan);
│ l2cap_chan_hold(chan);
│ list_add(&chan->list, &conn->chan_l); ... (1)
└ mutex_unlock(&conn->chan_lock);
chan->conf_state ... (4) <- use after free
[free]
l2cap_conn_del
┌ mutex_lock(&conn->chan_lock);
│ foreach chan in conn->chan_l: ... (2)
│ l2cap_chan_put(chan);
│ l2cap_chan_destroy
│ kfree(chan) ... (3) <- chan freed
└ mutex_unlock(&conn->chan_lock);
==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read
include/linux/instrumented.h:68 [inline]
BUG: KASAN: slab-use-after-free in _test_bit
include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: slab-use-after-free in l2cap_connect+0xa67/0x11a0
net/bluetooth/l2cap_core.c:4260
Read of size 8 at addr ffff88810bf040a0 by task kworker/u3:1/311
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix race between searching chunks and release journal_head from buffer_head
Encountered a race between ocfs2_test_bg_bit_allocatable() and
jbd2_journal_put_journal_head() resulting in the below vmcore.
PID: 106879 TASK: ffff880244ba9c00 CPU: 2 COMMAND: "loop3"
Call trace:
panic
oops_end
no_context
__bad_area_nosemaphore
bad_area_nosemaphore
__do_page_fault
do_page_fault
page_fault
[exception RIP: ocfs2_block_group_find_clear_bits+316]
ocfs2_block_group_find_clear_bits [ocfs2]
ocfs2_cluster_group_search [ocfs2]
ocfs2_search_chain [ocfs2]
ocfs2_claim_suballoc_bits [ocfs2]
__ocfs2_claim_clusters [ocfs2]
ocfs2_claim_clusters [ocfs2]
ocfs2_local_alloc_slide_window [ocfs2]
ocfs2_reserve_local_alloc_bits [ocfs2]
ocfs2_reserve_clusters_with_limit [ocfs2]
ocfs2_reserve_clusters [ocfs2]
ocfs2_lock_refcount_allocators [ocfs2]
ocfs2_make_clusters_writable [ocfs2]
ocfs2_replace_cow [ocfs2]
ocfs2_refcount_cow [ocfs2]
ocfs2_file_write_iter [ocfs2]
lo_rw_aio
loop_queue_work
kthread_worker_fn
kthread
ret_from_fork
When ocfs2_test_bg_bit_allocatable() called bh2jh(bg_bh), the
bg_bh->b_private NULL as jbd2_journal_put_journal_head() raced and
released the jounal head from the buffer head. Needed to take bit lock
for the bit 'BH_JournalHead' to fix this race.
In the Linux kernel, the following vulnerability has been resolved:
usbnet: sanity check for maxpacket
maxpacket of 0 makes no sense and oopses as we need to divide
by it. Give up.
V2: fixed typo in log and stylistic issues