Hello Ian and maintainers,
Just a gentle ping on this patch. It's been 10 days since v2 was sent
incorporating Ian's feedback to merge the chanlist_len check with the
existing early return.
Please let me know if any further changes are needed.
Thank you,
Deepanshu
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 40b7a19f321e65789612ebaca966472055dab48c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025100341-dime-left-e15f@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 40b7a19f321e65789612ebaca966472055dab48c Mon Sep 17 00:00:00 2001
From: Duoming Zhou <duoming(a)zju.edu.cn>
Date: Wed, 17 Sep 2025 17:56:08 +0800
Subject: [PATCH] media: tuner: xc5000: Fix use-after-free in xc5000_release
The original code uses cancel_delayed_work() in xc5000_release(), which
does not guarantee that the delayed work item timer_sleep has fully
completed if it was already running. This leads to use-after-free scenarios
where xc5000_release() may free the xc5000_priv while timer_sleep is still
active and attempts to dereference the xc5000_priv.
A typical race condition is illustrated below:
CPU 0 (release thread) | CPU 1 (delayed work callback)
xc5000_release() | xc5000_do_timer_sleep()
cancel_delayed_work() |
hybrid_tuner_release_state(priv) |
kfree(priv) |
| priv = container_of() // UAF
Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure
that the timer_sleep is properly canceled before the xc5000_priv memory
is deallocated.
A deadlock concern was considered: xc5000_release() is called in a process
context and is not holding any locks that the timer_sleep work item might
also need. Therefore, the use of the _sync() variant is safe here.
This bug was initially identified through static analysis.
Fixes: f7a27ff1fb77 ("[media] xc5000: delay tuner sleep to 5 seconds")
Cc: stable(a)vger.kernel.org
Signed-off-by: Duoming Zhou <duoming(a)zju.edu.cn>
Signed-off-by: Hans Verkuil <hverkuil+cisco(a)kernel.org>
[hverkuil: fix typo in Subject: tunner -> tuner]
diff --git a/drivers/media/tuners/xc5000.c b/drivers/media/tuners/xc5000.c
index bf4ff461e082..a28481edd22e 100644
--- a/drivers/media/tuners/xc5000.c
+++ b/drivers/media/tuners/xc5000.c
@@ -1304,7 +1304,7 @@ static void xc5000_release(struct dvb_frontend *fe)
mutex_lock(&xc5000_list_mutex);
if (priv) {
- cancel_delayed_work(&priv->timer_sleep);
+ cancel_delayed_work_sync(&priv->timer_sleep);
hybrid_tuner_release_state(priv);
}
Hi,
Please backport:
commit a40282dd3c48 ("gcc-plugins: Remove TODO_verify_il for GCC >= 16")
to all stable kernel versions. This prepares the GCC plugins for the
coming GCC 16 release.
Thanks!
-Kees
--
Kees Cook
The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 40b7a19f321e65789612ebaca966472055dab48c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025100341-cobbler-alabaster-748a@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 40b7a19f321e65789612ebaca966472055dab48c Mon Sep 17 00:00:00 2001
From: Duoming Zhou <duoming(a)zju.edu.cn>
Date: Wed, 17 Sep 2025 17:56:08 +0800
Subject: [PATCH] media: tuner: xc5000: Fix use-after-free in xc5000_release
The original code uses cancel_delayed_work() in xc5000_release(), which
does not guarantee that the delayed work item timer_sleep has fully
completed if it was already running. This leads to use-after-free scenarios
where xc5000_release() may free the xc5000_priv while timer_sleep is still
active and attempts to dereference the xc5000_priv.
A typical race condition is illustrated below:
CPU 0 (release thread) | CPU 1 (delayed work callback)
xc5000_release() | xc5000_do_timer_sleep()
cancel_delayed_work() |
hybrid_tuner_release_state(priv) |
kfree(priv) |
| priv = container_of() // UAF
Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure
that the timer_sleep is properly canceled before the xc5000_priv memory
is deallocated.
A deadlock concern was considered: xc5000_release() is called in a process
context and is not holding any locks that the timer_sleep work item might
also need. Therefore, the use of the _sync() variant is safe here.
This bug was initially identified through static analysis.
Fixes: f7a27ff1fb77 ("[media] xc5000: delay tuner sleep to 5 seconds")
Cc: stable(a)vger.kernel.org
Signed-off-by: Duoming Zhou <duoming(a)zju.edu.cn>
Signed-off-by: Hans Verkuil <hverkuil+cisco(a)kernel.org>
[hverkuil: fix typo in Subject: tunner -> tuner]
diff --git a/drivers/media/tuners/xc5000.c b/drivers/media/tuners/xc5000.c
index bf4ff461e082..a28481edd22e 100644
--- a/drivers/media/tuners/xc5000.c
+++ b/drivers/media/tuners/xc5000.c
@@ -1304,7 +1304,7 @@ static void xc5000_release(struct dvb_frontend *fe)
mutex_lock(&xc5000_list_mutex);
if (priv) {
- cancel_delayed_work(&priv->timer_sleep);
+ cancel_delayed_work_sync(&priv->timer_sleep);
hybrid_tuner_release_state(priv);
}
Guten Morgen,
mein Name ist Shun Tung, und ich vertrete die Interessen der Familie
Wing Mau, die an verschiedenen Investitionsmöglichkeiten in Ihrem Land
interessiert ist. Besonders interessieren wir uns für die Sektoren
Immobilien, Tourismus, erneuerbare Energien und Fertigung.
Aufgrund politischer Herausforderungen in unserem Heimatland suchen
wir einen zuverlässigen und vertrauenswürdigen Partner im Ausland, der
diese Investitionen in unserem Auftrag verwaltet und absichert.
Ihre Rolle würde darin bestehen, die Investitionen zu überwachen und
sicherzustellen, dass sie erfolgreich sind. Im Gegenzug würden Sie
einen vereinbarten Prozentsatz der Managementgebühren erhalten,
während die Gewinne gleichmäßig zwischen beiden Parteien aufgeteilt
werden.
Falls dieses Angebot Ihr Interesse weckt, würde ich mich über ein
weiteres Gespräch freuen. Ich freue mich auf Ihre Antwort.
Mit freundlichen Grüßen,
Shun Tung
From: Kuniyuki Iwashima <kuniyu(a)amazon.com>
[ Upstream commit df207de9d9e7a4d92f8567e2c539d9c8c12fd99d ]
Matt Dowling reported a weird UDP memory usage issue.
Under normal operation, the UDP memory usage reported in /proc/net/sockstat
remains close to zero. However, it occasionally spiked to 524,288 pages
and never dropped. Moreover, the value doubled when the application was
terminated. Finally, it caused intermittent packet drops.
We can reproduce the issue with the script below [0]:
1. /proc/net/sockstat reports 0 pages
# cat /proc/net/sockstat | grep UDP:
UDP: inuse 1 mem 0
2. Run the script till the report reaches 524,288
# python3 test.py & sleep 5
# cat /proc/net/sockstat | grep UDP:
UDP: inuse 3 mem 524288 <-- (INT_MAX + 1) >> PAGE_SHIFT
3. Kill the socket and confirm the number never drops
# pkill python3 && sleep 5
# cat /proc/net/sockstat | grep UDP:
UDP: inuse 1 mem 524288
4. (necessary since v6.0) Trigger proto_memory_pcpu_drain()
# python3 test.py & sleep 1 && pkill python3
5. The number doubles
# cat /proc/net/sockstat | grep UDP:
UDP: inuse 1 mem 1048577
The application set INT_MAX to SO_RCVBUF, which triggered an integer
overflow in udp_rmem_release().
When a socket is close()d, udp_destruct_common() purges its receive
queue and sums up skb->truesize in the queue. This total is calculated
and stored in a local unsigned integer variable.
The total size is then passed to udp_rmem_release() to adjust memory
accounting. However, because the function takes a signed integer
argument, the total size can wrap around, causing an overflow.
Then, the released amount is calculated as follows:
1) Add size to sk->sk_forward_alloc.
2) Round down sk->sk_forward_alloc to the nearest lower multiple of
PAGE_SIZE and assign it to amount.
3) Subtract amount from sk->sk_forward_alloc.
4) Pass amount >> PAGE_SHIFT to __sk_mem_reduce_allocated().
When the issue occurred, the total in udp_destruct_common() was 2147484480
(INT_MAX + 833), which was cast to -2147482816 in udp_rmem_release().
At 1) sk->sk_forward_alloc is changed from 3264 to -2147479552, and
2) sets -2147479552 to amount. 3) reverts the wraparound, so we don't
see a warning in inet_sock_destruct(). However, udp_memory_allocated
ends up doubling at 4).
Since commit 3cd3399dd7a8 ("net: implement per-cpu reserves for
memory_allocated"), memory usage no longer doubles immediately after
a socket is close()d because __sk_mem_reduce_allocated() caches the
amount in udp_memory_per_cpu_fw_alloc. However, the next time a UDP
socket receives a packet, the subtraction takes effect, causing UDP
memory usage to double.
This issue makes further memory allocation fail once the socket's
sk->sk_rmem_alloc exceeds net.ipv4.udp_rmem_min, resulting in packet
drops.
To prevent this issue, let's use unsigned int for the calculation and
call sk_forward_alloc_add() only once for the small delta.
Note that first_packet_length() also potentially has the same problem.
[0]:
from socket import *
SO_RCVBUFFORCE = 33
INT_MAX = (2 ** 31) - 1
s = socket(AF_INET, SOCK_DGRAM)
s.bind(('', 0))
s.setsockopt(SOL_SOCKET, SO_RCVBUFFORCE, INT_MAX)
c = socket(AF_INET, SOCK_DGRAM)
c.connect(s.getsockname())
data = b'a' * 100
while True:
c.send(data)
Fixes: f970bd9e3a06 ("udp: implement memory accounting helpers")
Reported-by: Matt Dowling <madowlin(a)amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu(a)amazon.com>
Reviewed-by: Willem de Bruijn <willemb(a)google.com>
Link: https://patch.msgid.link/20250401184501.67377-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba(a)kernel.org>
(cherry picked from commit df207de9d9e7a4d92f8567e2c539d9c8c12fd99d)
[Yifei: resolve minor conflicts and fix CVE-2025-22058]
Signed-off-by: Yifei Liu <yifei.l.liu(a)oracle.com>
---
net/ipv4/udp.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 51a12fa486b6..3ebd5765fb9f 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1459,12 +1459,12 @@ static bool udp_skb_has_head_state(struct sk_buff *skb)
}
/* fully reclaim rmem/fwd memory allocated for skb */
-static void udp_rmem_release(struct sock *sk, int size, int partial,
- bool rx_queue_lock_held)
+static void udp_rmem_release(struct sock *sk, unsigned int size,
+ int partial, bool rx_queue_lock_held)
{
struct udp_sock *up = udp_sk(sk);
struct sk_buff_head *sk_queue;
- int amt;
+ unsigned int amt;
if (likely(partial)) {
up->forward_deficit += size;
@@ -1484,10 +1484,8 @@ static void udp_rmem_release(struct sock *sk, int size, int partial,
if (!rx_queue_lock_held)
spin_lock(&sk_queue->lock);
-
- sk->sk_forward_alloc += size;
- amt = (sk->sk_forward_alloc - partial) & ~(SK_MEM_QUANTUM - 1);
- sk->sk_forward_alloc -= amt;
+ amt = (size + sk->sk_forward_alloc - partial) & ~(PAGE_SIZE - 1);
+ sk->sk_forward_alloc += size - amt;
if (amt)
__sk_mem_reduce_allocated(sk, amt >> SK_MEM_QUANTUM_SHIFT);
@@ -1671,7 +1669,7 @@ EXPORT_SYMBOL_GPL(skb_consume_udp);
static struct sk_buff *__first_packet_length(struct sock *sk,
struct sk_buff_head *rcvq,
- int *total)
+ unsigned int *total)
{
struct sk_buff *skb;
@@ -1704,8 +1702,8 @@ static int first_packet_length(struct sock *sk)
{
struct sk_buff_head *rcvq = &udp_sk(sk)->reader_queue;
struct sk_buff_head *sk_queue = &sk->sk_receive_queue;
+ unsigned int total = 0;
struct sk_buff *skb;
- int total = 0;
int res;
spin_lock_bh(&rcvq->lock);
--
2.50.1
From: Conor Dooley <conor.dooley(a)microchip.com>
The kernel uses the standard rustc targets for non-x86 targets, and out
of those only 64-bit arm's target has kcfi support enabled. For x86, the
custom 64-bit target enables kcfi.
The HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC config option that allows
CFI_CLANG to be used in combination with RUST does not check whether the
rustc target supports kcfi. This breaks the build on riscv (and
presumably 32-bit arm) when CFI_CLANG and RUST are enabled at the same
time.
Ordinarily, a rustc-option check would be used to detect target support
but unfortunately rustc-option filters out the target for reasons given
in commit 46e24a545cdb4 ("rust: kasan/kbuild: fix missing flags on first
build"). As a result, if the host supports kcfi but the target does not,
e.g. when building for riscv on x86_64, the build would remain broken.
Instead, make HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC depend on the only
two architectures where the target used supports it to fix the build.
CC: stable(a)vger.kernel.org
Fixes: ca627e636551e ("rust: cfi: add support for CFI_CLANG with Rust")
Signed-off-by: Conor Dooley <conor.dooley(a)microchip.com>
---
CC: Paul Walmsley <paul.walmsley(a)sifive.com>
CC: Palmer Dabbelt <palmer(a)dabbelt.com>
CC: Alexandre Ghiti <alex(a)ghiti.fr>
CC: Miguel Ojeda <ojeda(a)kernel.org>
CC: Alex Gaynor <alex.gaynor(a)gmail.com>
CC: Boqun Feng <boqun.feng(a)gmail.com>
CC: Gary Guo <gary(a)garyguo.net>
CC: "Björn Roy Baron" <bjorn3_gh(a)protonmail.com>
CC: Benno Lossin <lossin(a)kernel.org>
CC: Andreas Hindborg <a.hindborg(a)kernel.org>
CC: Alice Ryhl <aliceryhl(a)google.com>
CC: Trevor Gross <tmgross(a)umich.edu>
CC: Danilo Krummrich <dakr(a)kernel.org>
CC: Kees Cook <kees(a)kernel.org>
CC: Sami Tolvanen <samitolvanen(a)google.com>
CC: Matthew Maurer <mmaurer(a)google.com>
CC: "Peter Zijlstra (Intel)" <peterz(a)infradead.org>
CC: linux-kernel(a)vger.kernel.org
CC: linux-riscv(a)lists.infradead.org
CC: rust-for-linux(a)vger.kernel.org
---
arch/Kconfig | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/Kconfig b/arch/Kconfig
index d1b4ffd6e0856..880cddff5eda7 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -917,6 +917,7 @@ config HAVE_CFI_ICALL_NORMALIZE_INTEGERS_RUSTC
def_bool y
depends on HAVE_CFI_ICALL_NORMALIZE_INTEGERS_CLANG
depends on RUSTC_VERSION >= 107900
+ depends on ARM64 || X86_64
# With GCOV/KASAN we need this fix: https://github.com/rust-lang/rust/pull/129373
depends on (RUSTC_LLVM_VERSION >= 190103 && RUSTC_VERSION >= 108200) || \
(!GCOV_KERNEL && !KASAN_GENERIC && !KASAN_SW_TAGS)
--
2.47.2
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x fa0f61cc1d828178aa921475a9b786e7fbb65ccb
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025100320-pout-unwired-1096@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From fa0f61cc1d828178aa921475a9b786e7fbb65ccb Mon Sep 17 00:00:00 2001
From: Larshin Sergey <Sergey.Larshin(a)kaspersky.com>
Date: Tue, 29 Jul 2025 13:13:32 +0300
Subject: [PATCH] media: rc: fix races with imon_disconnect()
Syzbot reports a KASAN issue as below:
BUG: KASAN: use-after-free in __create_pipe include/linux/usb.h:1945 [inline]
BUG: KASAN: use-after-free in send_packet+0xa2d/0xbc0 drivers/media/rc/imon.c:627
Read of size 4 at addr ffff8880256fb000 by task syz-executor314/4465
CPU: 2 PID: 4465 Comm: syz-executor314 Not tainted 6.0.0-rc1-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:317 [inline]
print_report.cold+0x2ba/0x6e9 mm/kasan/report.c:433
kasan_report+0xb1/0x1e0 mm/kasan/report.c:495
__create_pipe include/linux/usb.h:1945 [inline]
send_packet+0xa2d/0xbc0 drivers/media/rc/imon.c:627
vfd_write+0x2d9/0x550 drivers/media/rc/imon.c:991
vfs_write+0x2d7/0xdd0 fs/read_write.c:576
ksys_write+0x127/0x250 fs/read_write.c:631
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The iMON driver improperly releases the usb_device reference in
imon_disconnect without coordinating with active users of the
device.
Specifically, the fields usbdev_intf0 and usbdev_intf1 are not
protected by the users counter (ictx->users). During probe,
imon_init_intf0 or imon_init_intf1 increments the usb_device
reference count depending on the interface. However, during
disconnect, usb_put_dev is called unconditionally, regardless of
actual usage.
As a result, if vfd_write or other operations are still in
progress after disconnect, this can lead to a use-after-free of
the usb_device pointer.
Thread 1 vfd_write Thread 2 imon_disconnect
...
if
usb_put_dev(ictx->usbdev_intf0)
else
usb_put_dev(ictx->usbdev_intf1)
...
while
send_packet
if
pipe = usb_sndintpipe(
ictx->usbdev_intf0) UAF
else
pipe = usb_sndctrlpipe(
ictx->usbdev_intf0, 0) UAF
Guard access to usbdev_intf0 and usbdev_intf1 after disconnect by
checking ictx->disconnected in all writer paths. Add early return
with -ENODEV in send_packet(), vfd_write(), lcd_write() and
display_open() if the device is no longer present.
Set and read ictx->disconnected under ictx->lock to ensure memory
synchronization. Acquire the lock in imon_disconnect() before setting
the flag to synchronize with any ongoing operations.
Ensure writers exit early and safely after disconnect before the USB
core proceeds with cleanup.
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Reported-by: syzbot+f1a69784f6efe748c3bf(a)syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f1a69784f6efe748c3bf
Fixes: 21677cfc562a ("V4L/DVB: ir-core: add imon driver")
Cc: stable(a)vger.kernel.org
Signed-off-by: Larshin Sergey <Sergey.Larshin(a)kaspersky.com>
Signed-off-by: Sean Young <sean(a)mess.org>
Signed-off-by: Hans Verkuil <hverkuil+cisco(a)kernel.org>
diff --git a/drivers/media/rc/imon.c b/drivers/media/rc/imon.c
index 91d05aadced3..35b9e07003d8 100644
--- a/drivers/media/rc/imon.c
+++ b/drivers/media/rc/imon.c
@@ -531,7 +531,9 @@ static int display_open(struct inode *inode, struct file *file)
mutex_lock(&ictx->lock);
- if (!ictx->display_supported) {
+ if (ictx->disconnected) {
+ retval = -ENODEV;
+ } else if (!ictx->display_supported) {
pr_err("display not supported by device\n");
retval = -ENODEV;
} else if (ictx->display_isopen) {
@@ -595,6 +597,9 @@ static int send_packet(struct imon_context *ictx)
lockdep_assert_held(&ictx->lock);
+ if (ictx->disconnected)
+ return -ENODEV;
+
/* Check if we need to use control or interrupt urb */
if (!ictx->tx_control) {
pipe = usb_sndintpipe(ictx->usbdev_intf0,
@@ -949,12 +954,14 @@ static ssize_t vfd_write(struct file *file, const char __user *buf,
static const unsigned char vfd_packet6[] = {
0x01, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF };
- if (ictx->disconnected)
- return -ENODEV;
-
if (mutex_lock_interruptible(&ictx->lock))
return -ERESTARTSYS;
+ if (ictx->disconnected) {
+ retval = -ENODEV;
+ goto exit;
+ }
+
if (!ictx->dev_present_intf0) {
pr_err_ratelimited("no iMON device present\n");
retval = -ENODEV;
@@ -1029,11 +1036,13 @@ static ssize_t lcd_write(struct file *file, const char __user *buf,
int retval = 0;
struct imon_context *ictx = file->private_data;
- if (ictx->disconnected)
- return -ENODEV;
-
mutex_lock(&ictx->lock);
+ if (ictx->disconnected) {
+ retval = -ENODEV;
+ goto exit;
+ }
+
if (!ictx->display_supported) {
pr_err_ratelimited("no iMON display present\n");
retval = -ENODEV;
@@ -2507,7 +2516,11 @@ static void imon_disconnect(struct usb_interface *interface)
int ifnum;
ictx = usb_get_intfdata(interface);
+
+ mutex_lock(&ictx->lock);
ictx->disconnected = true;
+ mutex_unlock(&ictx->lock);
+
dev = ictx->dev;
ifnum = interface->cur_altsetting->desc.bInterfaceNumber;
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 40b7a19f321e65789612ebaca966472055dab48c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025100340-pleat-amusable-e5dc@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 40b7a19f321e65789612ebaca966472055dab48c Mon Sep 17 00:00:00 2001
From: Duoming Zhou <duoming(a)zju.edu.cn>
Date: Wed, 17 Sep 2025 17:56:08 +0800
Subject: [PATCH] media: tuner: xc5000: Fix use-after-free in xc5000_release
The original code uses cancel_delayed_work() in xc5000_release(), which
does not guarantee that the delayed work item timer_sleep has fully
completed if it was already running. This leads to use-after-free scenarios
where xc5000_release() may free the xc5000_priv while timer_sleep is still
active and attempts to dereference the xc5000_priv.
A typical race condition is illustrated below:
CPU 0 (release thread) | CPU 1 (delayed work callback)
xc5000_release() | xc5000_do_timer_sleep()
cancel_delayed_work() |
hybrid_tuner_release_state(priv) |
kfree(priv) |
| priv = container_of() // UAF
Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure
that the timer_sleep is properly canceled before the xc5000_priv memory
is deallocated.
A deadlock concern was considered: xc5000_release() is called in a process
context and is not holding any locks that the timer_sleep work item might
also need. Therefore, the use of the _sync() variant is safe here.
This bug was initially identified through static analysis.
Fixes: f7a27ff1fb77 ("[media] xc5000: delay tuner sleep to 5 seconds")
Cc: stable(a)vger.kernel.org
Signed-off-by: Duoming Zhou <duoming(a)zju.edu.cn>
Signed-off-by: Hans Verkuil <hverkuil+cisco(a)kernel.org>
[hverkuil: fix typo in Subject: tunner -> tuner]
diff --git a/drivers/media/tuners/xc5000.c b/drivers/media/tuners/xc5000.c
index bf4ff461e082..a28481edd22e 100644
--- a/drivers/media/tuners/xc5000.c
+++ b/drivers/media/tuners/xc5000.c
@@ -1304,7 +1304,7 @@ static void xc5000_release(struct dvb_frontend *fe)
mutex_lock(&xc5000_list_mutex);
if (priv) {
- cancel_delayed_work(&priv->timer_sleep);
+ cancel_delayed_work_sync(&priv->timer_sleep);
hybrid_tuner_release_state(priv);
}
The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 40b7a19f321e65789612ebaca966472055dab48c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025100339-scarring-buffoon-fbc5@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 40b7a19f321e65789612ebaca966472055dab48c Mon Sep 17 00:00:00 2001
From: Duoming Zhou <duoming(a)zju.edu.cn>
Date: Wed, 17 Sep 2025 17:56:08 +0800
Subject: [PATCH] media: tuner: xc5000: Fix use-after-free in xc5000_release
The original code uses cancel_delayed_work() in xc5000_release(), which
does not guarantee that the delayed work item timer_sleep has fully
completed if it was already running. This leads to use-after-free scenarios
where xc5000_release() may free the xc5000_priv while timer_sleep is still
active and attempts to dereference the xc5000_priv.
A typical race condition is illustrated below:
CPU 0 (release thread) | CPU 1 (delayed work callback)
xc5000_release() | xc5000_do_timer_sleep()
cancel_delayed_work() |
hybrid_tuner_release_state(priv) |
kfree(priv) |
| priv = container_of() // UAF
Replace cancel_delayed_work() with cancel_delayed_work_sync() to ensure
that the timer_sleep is properly canceled before the xc5000_priv memory
is deallocated.
A deadlock concern was considered: xc5000_release() is called in a process
context and is not holding any locks that the timer_sleep work item might
also need. Therefore, the use of the _sync() variant is safe here.
This bug was initially identified through static analysis.
Fixes: f7a27ff1fb77 ("[media] xc5000: delay tuner sleep to 5 seconds")
Cc: stable(a)vger.kernel.org
Signed-off-by: Duoming Zhou <duoming(a)zju.edu.cn>
Signed-off-by: Hans Verkuil <hverkuil+cisco(a)kernel.org>
[hverkuil: fix typo in Subject: tunner -> tuner]
diff --git a/drivers/media/tuners/xc5000.c b/drivers/media/tuners/xc5000.c
index bf4ff461e082..a28481edd22e 100644
--- a/drivers/media/tuners/xc5000.c
+++ b/drivers/media/tuners/xc5000.c
@@ -1304,7 +1304,7 @@ static void xc5000_release(struct dvb_frontend *fe)
mutex_lock(&xc5000_list_mutex);
if (priv) {
- cancel_delayed_work(&priv->timer_sleep);
+ cancel_delayed_work_sync(&priv->timer_sleep);
hybrid_tuner_release_state(priv);
}