In the Linux kernel, the following vulnerability has been resolved:
media: pci: tw68: Fix null-ptr-deref bug in buf prepare and finish
When the driver calls tw68_risc_buffer() to prepare the buffer, the
function call dma_alloc_coherent may fail, resulting in a empty buffer
buf->cpu. Later when we free the buffer or access the buffer, null ptr
deref is triggered.
This bug is similar to the following one:
https://git.linuxtv.org/media_stage.git/commit/?id=2b064d91440b33fba5b452f2d1b31f13ae911d71.
We believe the bug can be also dynamically triggered from user side.
Similarly, we fix this by checking the return value of tw68_risc_buffer()
and the value of buf->cpu before buffer free.
In the Linux kernel, the following vulnerability has been resolved:
btrfs: set_page_extent_mapped after read_folio in btrfs_cont_expand
While trying to get the subpage blocksize tests running, I hit the
following panic on generic/476
assertion failed: PagePrivate(page) && page->private, in fs/btrfs/subpage.c:229
kernel BUG at fs/btrfs/subpage.c:229!
Internal error: Oops - BUG: 00000000f2000800 [#1] SMP
CPU: 1 PID: 1453 Comm: fsstress Not tainted 6.4.0-rc7+ #12
Hardware name: QEMU KVM Virtual Machine, BIOS edk2-20230301gitf80f052277c8-26.fc38 03/01/2023
pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
pc : btrfs_subpage_assert+0xbc/0xf0
lr : btrfs_subpage_assert+0xbc/0xf0
Call trace:
btrfs_subpage_assert+0xbc/0xf0
btrfs_subpage_clear_checked+0x38/0xc0
btrfs_page_clear_checked+0x48/0x98
btrfs_truncate_block+0x5d0/0x6a8
btrfs_cont_expand+0x5c/0x528
btrfs_write_check.isra.0+0xf8/0x150
btrfs_buffered_write+0xb4/0x760
btrfs_do_write_iter+0x2f8/0x4b0
btrfs_file_write_iter+0x1c/0x30
do_iter_readv_writev+0xc8/0x158
do_iter_write+0x9c/0x210
vfs_iter_write+0x24/0x40
iter_file_splice_write+0x224/0x390
direct_splice_actor+0x38/0x68
splice_direct_to_actor+0x12c/0x260
do_splice_direct+0x90/0xe8
generic_copy_file_range+0x50/0x90
vfs_copy_file_range+0x29c/0x470
__arm64_sys_copy_file_range+0xcc/0x498
invoke_syscall.constprop.0+0x80/0xd8
do_el0_svc+0x6c/0x168
el0_svc+0x50/0x1b0
el0t_64_sync_handler+0x114/0x120
el0t_64_sync+0x194/0x198
This happens because during btrfs_cont_expand we'll get a page, set it
as mapped, and if it's not Uptodate we'll read it. However between the
read and re-locking the page we could have called release_folio() on the
page, but left the page in the file mapping. release_folio() can clear
the page private, and thus further down we blow up when we go to modify
the subpage bits.
Fix this by putting the set_page_extent_mapped() after the read. This
is safe because read_folio() will call set_page_extent_mapped() before
it does the read, and then if we clear page private but leave it on the
mapping we're completely safe re-setting set_page_extent_mapped(). With
this patch I can now run generic/476 without panicing.
In the Linux kernel, the following vulnerability has been resolved:
erofs: Fix detection of atomic context
Current check for atomic context is not sufficient as
z_erofs_decompressqueue_endio can be called under rcu lock
from blk_mq_flush_plug_list(). See the stacktrace [1]
In such case we should hand off the decompression work for async
processing rather than trying to do sync decompression in current
context. Patch fixes the detection by checking for
rcu_read_lock_any_held() and while at it use more appropriate
!in_task() check than in_atomic().
Background: Historically erofs would always schedule a kworker for
decompression which would incur the scheduling cost regardless of
the context. But z_erofs_decompressqueue_endio() may not always
be in atomic context and we could actually benefit from doing the
decompression in z_erofs_decompressqueue_endio() if we are in
thread context, for example when running with dm-verity.
This optimization was later added in patch [2] which has shown
improvement in performance benchmarks.
==============================================
[1] Problem stacktrace
[name:core&]BUG: sleeping function called from invalid context at kernel/locking/mutex.c:291
[name:core&]in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1615, name: CpuMonitorServi
[name:core&]preempt_count: 0, expected: 0
[name:core&]RCU nest depth: 1, expected: 0
CPU: 7 PID: 1615 Comm: CpuMonitorServi Tainted: G S W OE 6.1.25-android14-5-maybe-dirty-mainline #1
Hardware name: MT6897 (DT)
Call trace:
dump_backtrace+0x108/0x15c
show_stack+0x20/0x30
dump_stack_lvl+0x6c/0x8c
dump_stack+0x20/0x48
__might_resched+0x1fc/0x308
__might_sleep+0x50/0x88
mutex_lock+0x2c/0x110
z_erofs_decompress_queue+0x11c/0xc10
z_erofs_decompress_kickoff+0x110/0x1a4
z_erofs_decompressqueue_endio+0x154/0x180
bio_endio+0x1b0/0x1d8
__dm_io_complete+0x22c/0x280
clone_endio+0xe4/0x280
bio_endio+0x1b0/0x1d8
blk_update_request+0x138/0x3a4
blk_mq_plug_issue_direct+0xd4/0x19c
blk_mq_flush_plug_list+0x2b0/0x354
__blk_flush_plug+0x110/0x160
blk_finish_plug+0x30/0x4c
read_pages+0x2fc/0x370
page_cache_ra_unbounded+0xa4/0x23c
page_cache_ra_order+0x290/0x320
do_sync_mmap_readahead+0x108/0x2c0
filemap_fault+0x19c/0x52c
__do_fault+0xc4/0x114
handle_mm_fault+0x5b4/0x1168
do_page_fault+0x338/0x4b4
do_translation_fault+0x40/0x60
do_mem_abort+0x60/0xc8
el0_da+0x4c/0xe0
el0t_64_sync_handler+0xd4/0xfc
el0t_64_sync+0x1a0/0x1a4
[2] Link: https://lore.kernel.org/all/20210317035448.13921-1-huangjianan@oppo.com/
In the Linux kernel, the following vulnerability has been resolved:
spi: imx: Don't skip cleanup in remove's error path
Returning early in a platform driver's remove callback is wrong. In this
case the dma resources are not released in the error path. this is never
retried later and so this is a permanent leak. To fix this, only skip
hardware disabling if waking the device fails.
In the Linux kernel, the following vulnerability has been resolved:
smb: client: fix warning in cifs_smb3_do_mount()
This fixes the following warning reported by kernel test robot
fs/smb/client/cifsfs.c:982 cifs_smb3_do_mount() warn: possible
memory leak of 'cifs_sb'
In the Linux kernel, the following vulnerability has been resolved:
rxrpc: Make it so that a waiting process can be aborted
When sendmsg() creates an rxrpc call, it queues it to wait for a connection
and channel to be assigned and then waits before it can start shovelling
data as the encrypted DATA packet content includes a summary of the
connection parameters.
However, sendmsg() may get interrupted before a connection gets assigned
and further sendmsg() calls will fail with EBUSY until an assignment is
made.
Fix this so that the call can at least be aborted without failing on
EBUSY. We have to be careful here as sendmsg() mustn't be allowed to start
the call timer if the call doesn't yet have a connection assigned as an
oops may follow shortly thereafter.
In the Linux kernel, the following vulnerability has been resolved:
wifi: mac80211_hwsim: Fix possible NULL dereference
In a call to mac80211_hwsim_select_tx_link() the sta pointer might
be NULL, thus need to check that it is not NULL before accessing it.
In the Linux kernel, the following vulnerability has been resolved:
netfilter: x_tables: fix percpu counter block leak on error path when creating new netns
Here is the stack where we allocate percpu counter block:
+-< __alloc_percpu
+-< xt_percpu_counter_alloc
+-< find_check_entry # {arp,ip,ip6}_tables.c
+-< translate_table
And it can be leaked on this code path:
+-> ip6t_register_table
+-> translate_table # allocates percpu counter block
+-> xt_register_table # fails
there is no freeing of the counter block on xt_register_table fail.
Note: xt_percpu_counter_free should be called to free it like we do in
do_replace through cleanup_entry helper (or in __ip6t_unregister_table).
Probability of hitting this error path is low AFAICS (xt_register_table
can only return ENOMEM here, as it is not replacing anything, as we are
creating new netns, and it is hard to imagine that all previous
allocations succeeded and after that one in xt_register_table failed).
But it's worth fixing even the rare leak.
In the Linux kernel, the following vulnerability has been resolved:
RDMA/bnxt_re: wraparound mbox producer index
Driver is not handling the wraparound of the mbox producer index correctly.
Currently the wraparound happens once u32 max is reached.
Bit 31 of the producer index register is special and should be set
only once for the first command. Because the producer index overflow
setting bit31 after a long time, FW goes to initialization sequence
and this causes FW hang.
Fix is to wraparound the mbox producer index once it reaches u16 max.