Linux: >> Linux Kernel >> 3.10.106 Security Vulnerabilities
In the Linux kernel, the following vulnerability has been resolved:
serial: 8250: fix panic due to PSLVERR
When the PSLVERR_RESP_EN parameter is set to 1, the device generates
an error response if an attempt is made to read an empty RBR (Receive
Buffer Register) while the FIFO is enabled.
In serial8250_do_startup(), calling serial_port_out(port, UART_LCR,
UART_LCR_WLEN8) triggers dw8250_check_lcr(), which invokes
dw8250_force_idle() and serial8250_clear_and_reinit_fifos(). The latter
function enables the FIFO via serial_out(p, UART_FCR, p->fcr).
Execution proceeds to the serial_port_in(port, UART_RX).
This satisfies the PSLVERR trigger condition.
When another CPU (e.g., using printk()) is accessing the UART (UART
is busy), the current CPU fails the check (value & ~UART_LCR_SPAR) ==
(lcr & ~UART_LCR_SPAR) in dw8250_check_lcr(), causing it to enter
dw8250_force_idle().
Put serial_port_out(port, UART_LCR, UART_LCR_WLEN8) under the port->lock
to fix this issue.
Panic backtrace:
[ 0.442336] Oops - unknown exception [#1]
[ 0.442343] epc : dw8250_serial_in32+0x1e/0x4a
[ 0.442351] ra : serial8250_do_startup+0x2c8/0x88e
...
[ 0.442416] console_on_rootfs+0x26/0x70
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-05
In the Linux kernel, the following vulnerability has been resolved:
parisc: Revise __get_user() to probe user read access
Because of the way read access support is implemented, read access
interruptions are only triggered at privilege levels 2 and 3. The
kernel executes at privilege level 0, so __get_user() never triggers
a read access interruption (code 26). Thus, it is currently possible
for user code to access a read protected address via a system call.
Fix this by probing read access rights at privilege level 3 (PRIV_USER)
and setting __gu_err to -EFAULT (-14) if access isn't allowed.
Note the cmpiclr instruction does a 32-bit compare because COND macro
doesn't work inside asm.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-05
In the Linux kernel, the following vulnerability has been resolved:
comedi: Fix use of uninitialized memory in do_insn_ioctl() and do_insnlist_ioctl()
syzbot reports a KMSAN kernel-infoleak in `do_insn_ioctl()`. A kernel
buffer is allocated to hold `insn->n` samples (each of which is an
`unsigned int`). For some instruction types, `insn->n` samples are
copied back to user-space, unless an error code is being returned. The
problem is that not all the instruction handlers that need to return
data to userspace fill in the whole `insn->n` samples, so that there is
an information leak. There is a similar syzbot report for
`do_insnlist_ioctl()`, although it does not have a reproducer for it at
the time of writing.
One culprit is `insn_rw_emulate_bits()` which is used as the handler for
`INSN_READ` or `INSN_WRITE` instructions for subdevices that do not have
a specific handler for that instruction, but do have an `INSN_BITS`
handler. For `INSN_READ` it only fills in at most 1 sample, so if
`insn->n` is greater than 1, the remaining `insn->n - 1` samples copied
to userspace will be uninitialized kernel data.
Another culprit is `vm80xx_ai_insn_read()` in the "vm80xx" driver. It
never returns an error, even if it fails to fill the buffer.
Fix it in `do_insn_ioctl()` and `do_insnlist_ioctl()` by making sure
that uninitialized parts of the allocated buffer are zeroed before
handling each instruction.
Thanks to Arnaud Lecomte for their fix to `do_insn_ioctl()`. That fix
replaced the call to `kmalloc_array()` with `kcalloc()`, but it is not
always necessary to clear the whole buffer.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-05
In the Linux kernel, the following vulnerability has been resolved:
comedi: Make insn_rw_emulate_bits() do insn->n samples
The `insn_rw_emulate_bits()` function is used as a default handler for
`INSN_READ` instructions for subdevices that have a handler for
`INSN_BITS` but not for `INSN_READ`. Similarly, it is used as a default
handler for `INSN_WRITE` instructions for subdevices that have a handler
for `INSN_BITS` but not for `INSN_WRITE`. It works by emulating the
`INSN_READ` or `INSN_WRITE` instruction handling with a constructed
`INSN_BITS` instruction. However, `INSN_READ` and `INSN_WRITE`
instructions are supposed to be able read or write multiple samples,
indicated by the `insn->n` value, but `insn_rw_emulate_bits()` currently
only handles a single sample. For `INSN_READ`, the comedi core will
copy `insn->n` samples back to user-space. (That triggered KASAN
kernel-infoleak errors when `insn->n` was greater than 1, but that is
being fixed more generally elsewhere in the comedi core.)
Make `insn_rw_emulate_bits()` either handle `insn->n` samples, or return
an error, to conform to the general expectation for `INSN_READ` and
`INSN_WRITE` handlers.
CVSS Score
7.8
EPSS Score
0.0
Published
2025-09-05
In the Linux kernel, the following vulnerability has been resolved:
fs/buffer: fix use-after-free when call bh_read() helper
There's issue as follows:
BUG: KASAN: stack-out-of-bounds in end_buffer_read_sync+0xe3/0x110
Read of size 8 at addr ffffc9000168f7f8 by task swapper/3/0
CPU: 3 UID: 0 PID: 0 Comm: swapper/3 Not tainted 6.16.0-862.14.0.6.x86_64
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
Call Trace:
<IRQ>
dump_stack_lvl+0x55/0x70
print_address_description.constprop.0+0x2c/0x390
print_report+0xb4/0x270
kasan_report+0xb8/0xf0
end_buffer_read_sync+0xe3/0x110
end_bio_bh_io_sync+0x56/0x80
blk_update_request+0x30a/0x720
scsi_end_request+0x51/0x2b0
scsi_io_completion+0xe3/0x480
? scsi_device_unbusy+0x11e/0x160
blk_complete_reqs+0x7b/0x90
handle_softirqs+0xef/0x370
irq_exit_rcu+0xa5/0xd0
sysvec_apic_timer_interrupt+0x6e/0x90
</IRQ>
Above issue happens when do ntfs3 filesystem mount, issue may happens
as follows:
mount IRQ
ntfs_fill_super
read_cache_page
do_read_cache_folio
filemap_read_folio
mpage_read_folio
do_mpage_readpage
ntfs_get_block_vbo
bh_read
submit_bh
wait_on_buffer(bh);
blk_complete_reqs
scsi_io_completion
scsi_end_request
blk_update_request
end_bio_bh_io_sync
end_buffer_read_sync
__end_buffer_read_notouch
unlock_buffer
wait_on_buffer(bh);--> return will return to caller
put_bh
--> trigger stack-out-of-bounds
In the mpage_read_folio() function, the stack variable 'map_bh' is
passed to ntfs_get_block_vbo(). Once unlock_buffer() unlocks and
wait_on_buffer() returns to continue processing, the stack variable
is likely to be reclaimed. Consequently, during the end_buffer_read_sync()
process, calling put_bh() may result in stack overrun.
If the bh is not allocated on the stack, it belongs to a folio. Freeing
a buffer head which belongs to a folio is done by drop_buffers() which
will fail to free buffers which are still locked. So it is safe to call
put_bh() before __end_buffer_read_notouch().
CVSS Score
7.8
EPSS Score
0.0
Published
2025-09-05
In the Linux kernel, the following vulnerability has been resolved:
net/sched: Fix backlog accounting in qdisc_dequeue_internal
This issue applies for the following qdiscs: hhf, fq, fq_codel, and
fq_pie, and occurs in their change handlers when adjusting to the new
limit. The problem is the following in the values passed to the
subsequent qdisc_tree_reduce_backlog call given a tbf parent:
When the tbf parent runs out of tokens, skbs of these qdiscs will
be placed in gso_skb. Their peek handlers are qdisc_peek_dequeued,
which accounts for both qlen and backlog. However, in the case of
qdisc_dequeue_internal, ONLY qlen is accounted for when pulling
from gso_skb. This means that these qdiscs are missing a
qdisc_qstats_backlog_dec when dropping packets to satisfy the
new limit in their change handlers.
One can observe this issue with the following (with tc patched to
support a limit of 0):
export TARGET=fq
tc qdisc del dev lo root
tc qdisc add dev lo root handle 1: tbf rate 8bit burst 100b latency 1ms
tc qdisc replace dev lo handle 3: parent 1:1 $TARGET limit 1000
echo ''; echo 'add child'; tc -s -d qdisc show dev lo
ping -I lo -f -c2 -s32 -W0.001 127.0.0.1 2>&1 >/dev/null
echo ''; echo 'after ping'; tc -s -d qdisc show dev lo
tc qdisc change dev lo handle 3: parent 1:1 $TARGET limit 0
echo ''; echo 'after limit drop'; tc -s -d qdisc show dev lo
tc qdisc replace dev lo handle 2: parent 1:1 sfq
echo ''; echo 'post graft'; tc -s -d qdisc show dev lo
The second to last show command shows 0 packets but a positive
number (74) of backlog bytes. The problem becomes clearer in the
last show command, where qdisc_purge_queue triggers
qdisc_tree_reduce_backlog with the positive backlog and causes an
underflow in the tbf parent's backlog (4096 Mb instead of 0).
To fix this issue, the codepath for all clients of qdisc_dequeue_internal
has been simplified: codel, pie, hhf, fq, fq_pie, and fq_codel.
qdisc_dequeue_internal handles the backlog adjustments for all cases that
do not directly use the dequeue handler.
The old fq_codel_change limit adjustment loop accumulated the arguments to
the subsequent qdisc_tree_reduce_backlog call through the cstats field.
However, this is confusing and error prone as fq_codel_dequeue could also
potentially mutate this field (which qdisc_dequeue_internal calls in the
non gso_skb case), so we have unified the code here with other qdiscs.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-05
In the Linux kernel, the following vulnerability has been resolved:
scsi: qla4xxx: Prevent a potential error pointer dereference
The qla4xxx_get_ep_fwdb() function is supposed to return NULL on error,
but qla4xxx_ep_connect() returns error pointers. Propagating the error
pointers will lead to an Oops in the caller, so change the error pointers
to NULL.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-05
In the Linux kernel, the following vulnerability has been resolved:
hfs: fix general protection fault in hfs_find_init()
The hfs_find_init() method can trigger the crash
if tree pointer is NULL:
[ 45.746290][ T9787] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] SMP KAI
[ 45.747287][ T9787] KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047]
[ 45.748716][ T9787] CPU: 2 UID: 0 PID: 9787 Comm: repro Not tainted 6.16.0-rc3 #10 PREEMPT(full)
[ 45.750250][ T9787] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 45.751983][ T9787] RIP: 0010:hfs_find_init+0x86/0x230
[ 45.752834][ T9787] Code: c1 ea 03 80 3c 02 00 0f 85 9a 01 00 00 4c 8d 6b 40 48 c7 45 18 00 00 00 00 48 b8 00 00 00 00 00 fc
[ 45.755574][ T9787] RSP: 0018:ffffc90015157668 EFLAGS: 00010202
[ 45.756432][ T9787] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff819a4d09
[ 45.757457][ T9787] RDX: 0000000000000008 RSI: ffffffff819acd3a RDI: ffffc900151576e8
[ 45.758282][ T9787] RBP: ffffc900151576d0 R08: 0000000000000005 R09: 0000000000000000
[ 45.758943][ T9787] R10: 0000000080000000 R11: 0000000000000001 R12: 0000000000000004
[ 45.759619][ T9787] R13: 0000000000000040 R14: ffff88802c50814a R15: 0000000000000000
[ 45.760293][ T9787] FS: 00007ffb72734540(0000) GS:ffff8880cec64000(0000) knlGS:0000000000000000
[ 45.761050][ T9787] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 45.761606][ T9787] CR2: 00007f9bd8225000 CR3: 000000010979a000 CR4: 00000000000006f0
[ 45.762286][ T9787] Call Trace:
[ 45.762570][ T9787] <TASK>
[ 45.762824][ T9787] hfs_ext_read_extent+0x190/0x9d0
[ 45.763269][ T9787] ? submit_bio_noacct_nocheck+0x2dd/0xce0
[ 45.763766][ T9787] ? __pfx_hfs_ext_read_extent+0x10/0x10
[ 45.764250][ T9787] hfs_get_block+0x55f/0x830
[ 45.764646][ T9787] block_read_full_folio+0x36d/0x850
[ 45.765105][ T9787] ? __pfx_hfs_get_block+0x10/0x10
[ 45.765541][ T9787] ? const_folio_flags+0x5b/0x100
[ 45.765972][ T9787] ? __pfx_hfs_read_folio+0x10/0x10
[ 45.766415][ T9787] filemap_read_folio+0xbe/0x290
[ 45.766840][ T9787] ? __pfx_filemap_read_folio+0x10/0x10
[ 45.767325][ T9787] ? __filemap_get_folio+0x32b/0xbf0
[ 45.767780][ T9787] do_read_cache_folio+0x263/0x5c0
[ 45.768223][ T9787] ? __pfx_hfs_read_folio+0x10/0x10
[ 45.768666][ T9787] read_cache_page+0x5b/0x160
[ 45.769070][ T9787] hfs_btree_open+0x491/0x1740
[ 45.769481][ T9787] hfs_mdb_get+0x15e2/0x1fb0
[ 45.769877][ T9787] ? __pfx_hfs_mdb_get+0x10/0x10
[ 45.770316][ T9787] ? find_held_lock+0x2b/0x80
[ 45.770731][ T9787] ? lockdep_init_map_type+0x5c/0x280
[ 45.771200][ T9787] ? lockdep_init_map_type+0x5c/0x280
[ 45.771674][ T9787] hfs_fill_super+0x38e/0x720
[ 45.772092][ T9787] ? __pfx_hfs_fill_super+0x10/0x10
[ 45.772549][ T9787] ? snprintf+0xbe/0x100
[ 45.772931][ T9787] ? __pfx_snprintf+0x10/0x10
[ 45.773350][ T9787] ? do_raw_spin_lock+0x129/0x2b0
[ 45.773796][ T9787] ? find_held_lock+0x2b/0x80
[ 45.774215][ T9787] ? set_blocksize+0x40a/0x510
[ 45.774636][ T9787] ? sb_set_blocksize+0x176/0x1d0
[ 45.775087][ T9787] ? setup_bdev_super+0x369/0x730
[ 45.775533][ T9787] get_tree_bdev_flags+0x384/0x620
[ 45.775985][ T9787] ? __pfx_hfs_fill_super+0x10/0x10
[ 45.776453][ T9787] ? __pfx_get_tree_bdev_flags+0x10/0x10
[ 45.776950][ T9787] ? bpf_lsm_capable+0x9/0x10
[ 45.777365][ T9787] ? security_capable+0x80/0x260
[ 45.777803][ T9787] vfs_get_tree+0x8e/0x340
[ 45.778203][ T9787] path_mount+0x13de/0x2010
[ 45.778604][ T9787] ? kmem_cache_free+0x2b0/0x4c0
[ 45.779052][ T9787] ? __pfx_path_mount+0x10/0x10
[ 45.779480][ T9787] ? getname_flags.part.0+0x1c5/0x550
[ 45.779954][ T9787] ? putname+0x154/0x1a0
[ 45.780335][ T9787] __x64_sys_mount+0x27b/0x300
[ 45.780758][ T9787] ? __pfx___x64_sys_mount+0x10/0x10
[ 45.781232][ T9787]
---truncated---
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-04
In the Linux kernel, the following vulnerability has been resolved:
netfilter: ctnetlink: fix refcount leak on table dump
There is a reference count leak in ctnetlink_dump_table():
if (res < 0) {
nf_conntrack_get(&ct->ct_general); // HERE
cb->args[1] = (unsigned long)ct;
...
While its very unlikely, its possible that ct == last.
If this happens, then the refcount of ct was already incremented.
This 2nd increment is never undone.
This prevents the conntrack object from being released, which in turn
keeps prevents cnet->count from dropping back to 0.
This will then block the netns dismantle (or conntrack rmmod) as
nf_conntrack_cleanup_net_list() will wait forever.
This can be reproduced by running conntrack_resize.sh selftest in a loop.
It takes ~20 minutes for me on a preemptible kernel on average before
I see a runaway kworker spinning in nf_conntrack_cleanup_net_list.
One fix would to change this to:
if (res < 0) {
if (ct != last)
nf_conntrack_get(&ct->ct_general);
But this reference counting isn't needed in the first place.
We can just store a cookie value instead.
A followup patch will do the same for ctnetlink_exp_dump_table,
it looks to me as if this has the same problem and like
ctnetlink_dump_table, we only need a 'skip hint', not the actual
object so we can apply the same cookie strategy there as well.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-04
In the Linux kernel, the following vulnerability has been resolved:
gfs2: Validate i_depth for exhash directories
A fuzzer test introduced corruption that ends up with a depth of 0 in
dir_e_read(), causing an undefined shift by 32 at:
index = hash >> (32 - dip->i_depth);
As calculated in an open-coded way in dir_make_exhash(), the minimum
depth for an exhash directory is ilog2(sdp->sd_hash_ptrs) and 0 is
invalid as sdp->sd_hash_ptrs is fixed as sdp->bsize / 16 at mount time.
So we can avoid the undefined behaviour by checking for depth values
lower than the minimum in gfs2_dinode_in(). Values greater than the
maximum are already being checked for there.
Also switch the calculation in dir_make_exhash() to use ilog2() to
clarify how the depth is calculated.
Tested with the syzkaller repro.c and xfstests '-g quick'.
CVSS Score
5.5
EPSS Score
0.0
Published
2025-09-04