In the Linux kernel, the following vulnerability has been resolved:
media: cx88: Fix a null-ptr-deref bug in buffer_prepare()
When the driver calls cx88_risc_buffer() to prepare the buffer, the
function call may fail, resulting in a empty buffer and null-ptr-deref
later in buffer_queue().
The following log can reveal it:
[ 41.822762] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
[ 41.824488] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
[ 41.828027] RIP: 0010:buffer_queue+0xc2/0x500
[ 41.836311] Call Trace:
[ 41.836945] __enqueue_in_driver+0x141/0x360
[ 41.837262] vb2_start_streaming+0x62/0x4a0
[ 41.838216] vb2_core_streamon+0x1da/0x2c0
[ 41.838516] __vb2_init_fileio+0x981/0xbc0
[ 41.839141] __vb2_perform_fileio+0xbf9/0x1120
[ 41.840072] vb2_fop_read+0x20e/0x400
[ 41.840346] v4l2_read+0x215/0x290
[ 41.840603] vfs_read+0x162/0x4c0
Fix this by checking the return value of cx88_risc_buffer()
[hverkuil: fix coding style issues]
In the Linux kernel, the following vulnerability has been resolved:
recordmcount: Fix memory leaks in the uwrite function
Common realloc mistake: 'file_append' nulled but not freed upon failure
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: Fix use-after-free
Fix potential use-after-free in l2cap_le_command_rej.
In the Linux kernel, the following vulnerability has been resolved:
drm/radeon: Fix integer overflow in radeon_cs_parser_init
The type of size is unsigned, if size is 0x40000000, there will be an
integer overflow, size will be zero after size *= sizeof(uint32_t),
will cause uninitialized memory to be referenced later
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix null-ptr-deref in ext4_write_info
I caught a null-ptr-deref bug as follows:
==================================================================
KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
CPU: 1 PID: 1589 Comm: umount Not tainted 5.10.0-02219-dirty #339
RIP: 0010:ext4_write_info+0x53/0x1b0
[...]
Call Trace:
dquot_writeback_dquots+0x341/0x9a0
ext4_sync_fs+0x19e/0x800
__sync_filesystem+0x83/0x100
sync_filesystem+0x89/0xf0
generic_shutdown_super+0x79/0x3e0
kill_block_super+0xa1/0x110
deactivate_locked_super+0xac/0x130
deactivate_super+0xb6/0xd0
cleanup_mnt+0x289/0x400
__cleanup_mnt+0x16/0x20
task_work_run+0x11c/0x1c0
exit_to_user_mode_prepare+0x203/0x210
syscall_exit_to_user_mode+0x5b/0x3a0
do_syscall_64+0x59/0x70
entry_SYSCALL_64_after_hwframe+0x44/0xa9
==================================================================
Above issue may happen as follows:
-------------------------------------
exit_to_user_mode_prepare
task_work_run
__cleanup_mnt
cleanup_mnt
deactivate_super
deactivate_locked_super
kill_block_super
generic_shutdown_super
shrink_dcache_for_umount
dentry = sb->s_root
sb->s_root = NULL <--- Here set NULL
sync_filesystem
__sync_filesystem
sb->s_op->sync_fs > ext4_sync_fs
dquot_writeback_dquots
sb->dq_op->write_info > ext4_write_info
ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2)
d_inode(sb->s_root)
s_root->d_inode <--- Null pointer dereference
To solve this problem, we use ext4_journal_start_sb directly
to avoid s_root being used.
In the Linux kernel, the following vulnerability has been resolved:
cifs: fix oops during encryption
When running xfstests against Azure the following oops occurred on an
arm64 system
Unable to handle kernel write to read-only memory at virtual address
ffff0001221cf000
Mem abort info:
ESR = 0x9600004f
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x0f: level 3 permission fault
Data abort info:
ISV = 0, ISS = 0x0000004f
CM = 0, WnR = 1
swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000000294f3000
[ffff0001221cf000] pgd=18000001ffff8003, p4d=18000001ffff8003,
pud=18000001ff82e003, pmd=18000001ff71d003, pte=00600001221cf787
Internal error: Oops: 9600004f [#1] PREEMPT SMP
...
pstate: 80000005 (Nzcv daif -PAN -UAO -TCO BTYPE=--)
pc : __memcpy+0x40/0x230
lr : scatterwalk_copychunks+0xe0/0x200
sp : ffff800014e92de0
x29: ffff800014e92de0 x28: ffff000114f9de80 x27: 0000000000000008
x26: 0000000000000008 x25: ffff800014e92e78 x24: 0000000000000008
x23: 0000000000000001 x22: 0000040000000000 x21: ffff000000000000
x20: 0000000000000001 x19: ffff0001037c4488 x18: 0000000000000014
x17: 235e1c0d6efa9661 x16: a435f9576b6edd6c x15: 0000000000000058
x14: 0000000000000001 x13: 0000000000000008 x12: ffff000114f2e590
x11: ffffffffffffffff x10: 0000040000000000 x9 : ffff8000105c3580
x8 : 2e9413b10000001a x7 : 534b4410fb86b005 x6 : 534b4410fb86b005
x5 : ffff0001221cf008 x4 : ffff0001037c4490 x3 : 0000000000000001
x2 : 0000000000000008 x1 : ffff0001037c4488 x0 : ffff0001221cf000
Call trace:
__memcpy+0x40/0x230
scatterwalk_map_and_copy+0x98/0x100
crypto_ccm_encrypt+0x150/0x180
crypto_aead_encrypt+0x2c/0x40
crypt_message+0x750/0x880
smb3_init_transform_rq+0x298/0x340
smb_send_rqst.part.11+0xd8/0x180
smb_send_rqst+0x3c/0x100
compound_send_recv+0x534/0xbc0
smb2_query_info_compound+0x32c/0x440
smb2_set_ea+0x438/0x4c0
cifs_xattr_set+0x5d4/0x7c0
This is because in scatterwalk_copychunks(), we attempted to write to
a buffer (@sign) that was allocated in the stack (vmalloc area) by
crypt_message() and thus accessing its remaining 8 (x2) bytes ended up
crossing a page boundary.
To simply fix it, we could just pass @sign kmalloc'd from
crypt_message() and then we're done. Luckily, we don't seem to pass
any other vmalloc'd buffers in smb_rqst::rq_iov...
Instead, let's map the correct pages and offsets from vmalloc buffers
as well in cifs_sg_set_buf() and then avoiding such oopses.
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: fix "bad unlock balance" in l2cap_disconnect_rsp
conn->chan_lock isn't acquired before l2cap_get_chan_by_scid,
if l2cap_get_chan_by_scid returns NULL, then 'bad unlock balance'
is triggered.
In the Linux kernel, the following vulnerability has been resolved:
blk-mq: fix NULL dereference on q->elevator in blk_mq_elv_switch_none
After grabbing q->sysfs_lock, q->elevator may become NULL because of
elevator switch.
Fix the NULL dereference on q->elevator by checking it with lock.