In the Linux kernel, the following vulnerability has been resolved:
HSI: ssi_protocol: Fix use after free vulnerability in ssi_protocol Driver Due to Race Condition
In the ssi_protocol_probe() function, &ssi->work is bound with
ssip_xmit_work(), In ssip_pn_setup(), the ssip_pn_xmit() function
within the ssip_pn_ops structure is capable of starting the
work.
If we remove the module which will call ssi_protocol_remove()
to make a cleanup, it will free ssi through kfree(ssi),
while the work mentioned above will be used. The sequence
of operations that may lead to a UAF bug is as follows:
CPU0 CPU1
| ssip_xmit_work
ssi_protocol_remove |
kfree(ssi); |
| struct hsi_client *cl = ssi->cl;
| // use ssi
Fix it by ensuring that the work is canceled before proceeding
with the cleanup in ssi_protocol_remove().
In the Linux kernel, the following vulnerability has been resolved:
clk: samsung: Fix UBSAN panic in samsung_clk_init()
With UBSAN_ARRAY_BOUNDS=y, I'm hitting the below panic due to
dereferencing `ctx->clk_data.hws` before setting
`ctx->clk_data.num = nr_clks`. Move that up to fix the crash.
UBSAN: array index out of bounds: 00000000f2005512 [#1] PREEMPT SMP
<snip>
Call trace:
samsung_clk_init+0x110/0x124 (P)
samsung_clk_init+0x48/0x124 (L)
samsung_cmu_register_one+0x3c/0xa0
exynos_arm64_register_cmu+0x54/0x64
__gs101_cmu_top_of_clk_init_declare+0x28/0x60
...
In the Linux kernel, the following vulnerability has been resolved:
net_sched: skbprio: Remove overly strict queue assertions
In the current implementation, skbprio enqueue/dequeue contains an assertion
that fails under certain conditions when SKBPRIO is used as a child qdisc under
TBF with specific parameters. The failure occurs because TBF sometimes peeks at
packets in the child qdisc without actually dequeuing them when tokens are
unavailable.
This peek operation creates a discrepancy between the parent and child qdisc
queue length counters. When TBF later receives a high-priority packet,
SKBPRIO's queue length may show a different value than what's reflected in its
internal priority queue tracking, triggering the assertion.
The fix removes this overly strict assertions in SKBPRIO, they are not
necessary at all.
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix OOB read when checking dotdot dir
Mounting a corrupted filesystem with directory which contains '.' dir
entry with rec_len == block size results in out-of-bounds read (later
on, when the corrupted directory is removed).
ext4_empty_dir() assumes every ext4 directory contains at least '.'
and '..' as directory entries in the first data block. It first loads
the '.' dir entry, performs sanity checks by calling ext4_check_dir_entry()
and then uses its rec_len member to compute the location of '..' dir
entry (in ext4_next_entry). It assumes the '..' dir entry fits into the
same data block.
If the rec_len of '.' is precisely one block (4KB), it slips through the
sanity checks (it is considered the last directory entry in the data
block) and leaves "struct ext4_dir_entry_2 *de" point exactly past the
memory slot allocated to the data block. The following call to
ext4_check_dir_entry() on new value of de then dereferences this pointer
which results in out-of-bounds mem access.
Fix this by extending __ext4_check_dir_entry() to check for '.' dir
entries that reach the end of data block. Make sure to ignore the phony
dir entries for checksum (by checking name_len for non-zero).
Note: This is reported by KASAN as use-after-free in case another
structure was recently freed from the slot past the bound, but it is
really an OOB read.
This issue was found by syzkaller tool.
Call Trace:
[ 38.594108] BUG: KASAN: slab-use-after-free in __ext4_check_dir_entry+0x67e/0x710
[ 38.594649] Read of size 2 at addr ffff88802b41a004 by task syz-executor/5375
[ 38.595158]
[ 38.595288] CPU: 0 UID: 0 PID: 5375 Comm: syz-executor Not tainted 6.14.0-rc7 #1
[ 38.595298] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
[ 38.595304] Call Trace:
[ 38.595308] <TASK>
[ 38.595311] dump_stack_lvl+0xa7/0xd0
[ 38.595325] print_address_description.constprop.0+0x2c/0x3f0
[ 38.595339] ? __ext4_check_dir_entry+0x67e/0x710
[ 38.595349] print_report+0xaa/0x250
[ 38.595359] ? __ext4_check_dir_entry+0x67e/0x710
[ 38.595368] ? kasan_addr_to_slab+0x9/0x90
[ 38.595378] kasan_report+0xab/0xe0
[ 38.595389] ? __ext4_check_dir_entry+0x67e/0x710
[ 38.595400] __ext4_check_dir_entry+0x67e/0x710
[ 38.595410] ext4_empty_dir+0x465/0x990
[ 38.595421] ? __pfx_ext4_empty_dir+0x10/0x10
[ 38.595432] ext4_rmdir.part.0+0x29a/0xd10
[ 38.595441] ? __dquot_initialize+0x2a7/0xbf0
[ 38.595455] ? __pfx_ext4_rmdir.part.0+0x10/0x10
[ 38.595464] ? __pfx___dquot_initialize+0x10/0x10
[ 38.595478] ? down_write+0xdb/0x140
[ 38.595487] ? __pfx_down_write+0x10/0x10
[ 38.595497] ext4_rmdir+0xee/0x140
[ 38.595506] vfs_rmdir+0x209/0x670
[ 38.595517] ? lookup_one_qstr_excl+0x3b/0x190
[ 38.595529] do_rmdir+0x363/0x3c0
[ 38.595537] ? __pfx_do_rmdir+0x10/0x10
[ 38.595544] ? strncpy_from_user+0x1ff/0x2e0
[ 38.595561] __x64_sys_unlinkat+0xf0/0x130
[ 38.595570] do_syscall_64+0x5b/0x180
[ 38.595583] entry_SYSCALL_64_after_hwframe+0x76/0x7e
In the Linux kernel, the following vulnerability has been resolved:
can: dev: can_restart: fix use after free bug
After calling netif_rx_ni(skb), dereferencing skb is unsafe.
Especially, the can_frame cf which aliases skb memory is accessed
after the netif_rx_ni() in:
stats->rx_bytes += cf->len;
Reordering the lines solves the issue.
In the Linux kernel, the following vulnerability has been resolved:
can: vxcan: vxcan_xmit: fix use after free bug
After calling netif_rx_ni(skb), dereferencing skb is unsafe.
Especially, the canfd_frame cfd which aliases skb memory is accessed
after the netif_rx_ni().
In the Linux kernel, the following vulnerability has been resolved:
can: peak_usb: fix use after free bugs
After calling peak_usb_netif_rx_ni(skb), dereferencing skb is unsafe.
Especially, the can_frame cf which aliases skb memory is accessed
after the peak_usb_netif_rx_ni().
Reordering the lines solves the issue.
In the Linux kernel, the following vulnerability has been resolved:
can: dev: can_get_echo_skb(): prevent call to kfree_skb() in hard IRQ context
If a driver calls can_get_echo_skb() during a hardware IRQ (which is often, but
not always, the case), the 'WARN_ON(in_irq)' in
net/core/skbuff.c#skb_release_head_state() might be triggered, under network
congestion circumstances, together with the potential risk of a NULL pointer
dereference.
The root cause of this issue is the call to kfree_skb() instead of
dev_kfree_skb_irq() in net/core/dev.c#enqueue_to_backlog().
This patch prevents the skb to be freed within the call to netif_rx() by
incrementing its reference count with skb_get(). The skb is finally freed by
one of the in-irq-context safe functions: dev_consume_skb_any() or
dev_kfree_skb_any(). The "any" version is used because some drivers might call
can_get_echo_skb() in a normal context.
The reason for this issue to occur is that initially, in the core network
stack, loopback skb were not supposed to be received in hardware IRQ context.
The CAN stack is an exeption.
This bug was previously reported back in 2017 in [1] but the proposed patch
never got accepted.
While [1] directly modifies net/core/dev.c, we try to propose here a
smoother modification local to CAN network stack (the assumption
behind is that only CAN devices are affected by this issue).
[1] http://lore.kernel.org/r/57a3ffb6-3309-3ad5-5a34-e93c3fe3614d@cetitec.com
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to avoid panic once fallocation fails for pinfile
syzbot reports a f2fs bug as below:
------------[ cut here ]------------
kernel BUG at fs/f2fs/segment.c:2746!
CPU: 0 UID: 0 PID: 5323 Comm: syz.0.0 Not tainted 6.13.0-rc2-syzkaller-00018-g7cb1b4663150 #0
RIP: 0010:get_new_segment fs/f2fs/segment.c:2746 [inline]
RIP: 0010:new_curseg+0x1f52/0x1f70 fs/f2fs/segment.c:2876
Call Trace:
<TASK>
__allocate_new_segment+0x1ce/0x940 fs/f2fs/segment.c:3210
f2fs_allocate_new_section fs/f2fs/segment.c:3224 [inline]
f2fs_allocate_pinning_section+0xfa/0x4e0 fs/f2fs/segment.c:3238
f2fs_expand_inode_data+0x696/0xca0 fs/f2fs/file.c:1830
f2fs_fallocate+0x537/0xa10 fs/f2fs/file.c:1940
vfs_fallocate+0x569/0x6e0 fs/open.c:327
do_vfs_ioctl+0x258c/0x2e40 fs/ioctl.c:885
__do_sys_ioctl fs/ioctl.c:904 [inline]
__se_sys_ioctl+0x80/0x170 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Concurrent pinfile allocation may run out of free section, result in
panic in get_new_segment(), let's expand pin_sem lock coverage to
include f2fs_gc(), so that we can make sure to reclaim enough free
space for following allocation.
In addition, do below changes to enhance error path handling:
- call f2fs_bug_on() only in non-pinfile allocation path in
get_new_segment().
- call reset_curseg_fields() to reset all fields of curseg in
new_curseg()