In as102_usb driver, the following race condition occurs:
```
CPU0 CPU1
as102_usb_probe()
kzalloc(); // alloc as102_dev_t
....
usb_register_dev();
open("/path/to/dev"); // open as102 dev
....
usb_deregister_dev();
....
kfree(); // free as102_dev_t
....
close(fd);
as102_release() // UAF!!
as102_usb_release()
kfree(); // DFB!!
```
When a USB character device registered with usb_register_dev() is later
unregistered (via usb_deregister_dev() or disconnect), the device node is
removed so new open() calls fail. However, file descriptors that are
already open do not go away immediately: they remain valid until the last
reference is dropped and the driver's .release() is invoked.
In as102, as102_usb_probe() calls usb_register_dev() and then, on an
error path, does usb_deregister_dev() and frees as102_dev_t right away.
If userspace raced a successful open() before the deregistration, that
open FD will later hit as102_release() --> as102_usb_release() and access
or free as102_dev_t again, occur a race to use-after-free and
double-free vuln.
The fix is to never kfree(as102_dev_t) directly once usb_register_dev()
has succeeded. After deregistration, defer freeing memory to .release().
In other words, let release() perform the last kfree when the final open
FD is closed.
Cc: <stable(a)vger.kernel.org>
Reported-by: syzbot+47321e8fd5a4c84088db(a)syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=47321e8fd5a4c84088db
Fixes: cd19f7d3e39b ("[media] as102: fix leaks at failure paths in as102_usb_probe()")
Signed-off-by: Jeongjun Park <aha310510(a)gmail.com>
---
v2: Fix incorrect patch description style and CC stable mailing list
- Link to v1: https://lore.kernel.org/all/20250822143539.1157329-1-aha310510@gmail.com/
---
drivers/media/usb/as102/as102_usb_drv.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/media/usb/as102/as102_usb_drv.c b/drivers/media/usb/as102/as102_usb_drv.c
index e0ef66a522e2..abde5666b2ee 100644
--- a/drivers/media/usb/as102/as102_usb_drv.c
+++ b/drivers/media/usb/as102/as102_usb_drv.c
@@ -404,6 +404,7 @@ static int as102_usb_probe(struct usb_interface *intf,
as102_free_usb_stream_buffer(as102_dev);
failed_stream:
usb_deregister_dev(intf, &as102_usb_class_driver);
+ return ret;
failed:
usb_put_dev(as102_dev->bus_adap.usb_dev);
usb_set_intfdata(intf, NULL);
--
In hackrf driver, the following race condition occurs:
```
CPU0 CPU1
hackrf_probe()
kzalloc(); // alloc hackrf_dev
....
v4l2_device_register();
....
open("/path/to/dev"); // open hackrf dev
....
v4l2_device_unregister();
....
kfree(); // free hackrf_dev
....
ioctl(fd, ...);
v4l2_ioctl();
video_is_registered() // UAF!!
....
close(fd);
v4l2_release() // UAF!!
hackrf_video_release()
kfree(); // DFB!!
```
When a V4L2 or video device is unregistered, the device node is removed so
new open() calls are blocked.
However, file descriptors that are already open-and any in-flight I/O-do
not terminate immediately; they remain valid until the last reference is
dropped and the driver's release() is invoked.
Therefore, freeing device memory on the error path after hackrf_probe()
has registered dev it will lead to a race to use-after-free vuln, since
those already-open handles haven't been released yet.
And since release() free memory too, race to use-after-free and
double-free vuln occur.
To prevent this, if device is registered from probe(), it should be
modified to free memory only through release() rather than calling
kfree() directly.
Cc: <stable(a)vger.kernel.org>
Reported-by: syzbot+6ffd76b5405c006a46b7(a)syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6ffd76b5405c006a46b7
Reported-by: syzbot+f1b20958f93d2d250727(a)syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=f1b20958f93d2d250727
Fixes: 8bc4a9ed8504 ("[media] hackrf: add support for transmitter")
Signed-off-by: Jeongjun Park <aha310510(a)gmail.com>
---
v2: Fix incorrect patch description style and CC stable mailing list
- Link to v1: https://lore.kernel.org/all/20250822142729.1156816-1-aha310510@gmail.com/
---
drivers/media/usb/hackrf/hackrf.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/media/usb/hackrf/hackrf.c b/drivers/media/usb/hackrf/hackrf.c
index 0b50de8775a3..d7a84422193d 100644
--- a/drivers/media/usb/hackrf/hackrf.c
+++ b/drivers/media/usb/hackrf/hackrf.c
@@ -1515,6 +1515,8 @@ static int hackrf_probe(struct usb_interface *intf,
video_unregister_device(&dev->rx_vdev);
err_v4l2_device_unregister:
v4l2_device_unregister(&dev->v4l2_dev);
+ dev_dbg(&intf->dev, "failed=%d\n", ret);
+ return ret;
err_v4l2_ctrl_handler_free_tx:
v4l2_ctrl_handler_free(&dev->tx_ctrl_handler);
err_v4l2_ctrl_handler_free_rx:
--
VM fails to boot with 256 vCPUs, the detailed command is
qemu-system-loongarch64 -smp 256 and there is error reported as follows:
KVM_LOONGARCH_EXTIOI_INIT_NUM_CPU failed: Invalid argument
There is typo issue in function kvm_eiointc_ctrl_access() when set
max supported vCPUs.
Cc: stable(a)vger.kernel.org
Fixes: 47256c4c8b1b ("LoongArch: KVM: Avoid copy_*_user() with lock hold in kvm_eiointc_ctrl_access()")
Signed-off-by: Bibo Mao <maobibo(a)loongson.cn>
---
arch/loongarch/kvm/intc/eiointc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/loongarch/kvm/intc/eiointc.c b/arch/loongarch/kvm/intc/eiointc.c
index c32333695381..a1cc116b4dac 100644
--- a/arch/loongarch/kvm/intc/eiointc.c
+++ b/arch/loongarch/kvm/intc/eiointc.c
@@ -439,7 +439,7 @@ static int kvm_eiointc_ctrl_access(struct kvm_device *dev,
spin_lock_irqsave(&s->lock, flags);
switch (type) {
case KVM_DEV_LOONGARCH_EXTIOI_CTRL_INIT_NUM_CPU:
- if (val >= EIOINTC_ROUTE_MAX_VCPUS)
+ if (val > EIOINTC_ROUTE_MAX_VCPUS)
ret = -EINVAL;
else
s->num_cpu = val;
base-commit: 3a8660878839faadb4f1a6dd72c3179c1df56787
--
2.39.3
The following commit has been merged into the perf/urgent branch of tip:
Commit-ID: ebfc8542ad62d066771e46c8aa30f5624b89cad8
Gitweb: https://git.kernel.org/tip/ebfc8542ad62d066771e46c8aa30f5624b89cad8
Author: Adrian Hunter <adrian.hunter(a)intel.com>
AuthorDate: Mon, 13 Oct 2025 10:22:42 +03:00
Committer: Peter Zijlstra <peterz(a)infradead.org>
CommitterDate: Tue, 14 Oct 2025 10:38:09 +02:00
perf/core: Fix address filter match with backing files
It was reported that Intel PT address filters do not work in Docker
containers. That relates to the use of overlayfs.
overlayfs records the backing file in struct vm_area_struct vm_file,
instead of the user file that the user mmapped. In order for an address
filter to match, it must compare to the user file inode. There is an
existing helper file_user_inode() for that situation.
Use file_user_inode() instead of file_inode() to get the inode for address
filter matching.
Example:
Setup:
# cd /root
# mkdir test ; cd test ; mkdir lower upper work merged
# cp `which cat` lower
# mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged
# perf record --buildid-mmap -e intel_pt//u --filter 'filter * @ /root/test/merged/cat' -- /root/test/merged/cat /proc/self/maps
...
55d61d246000-55d61d2e1000 r-xp 00018000 00:1a 3418 /root/test/merged/cat
...
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.015 MB perf.data ]
# perf buildid-cache --add /root/test/merged/cat
Before:
Address filter does not match so there are no control flow packets
# perf script --itrace=e
# perf script --itrace=b | wc -l
0
# perf script -D | grep 'TIP.PGE' | wc -l
0
#
After:
Address filter does match so there are control flow packets
# perf script --itrace=e
# perf script --itrace=b | wc -l
235
# perf script -D | grep 'TIP.PGE' | wc -l
57
#
With respect to stable kernels, overlayfs mmap function ovl_mmap() was
added in v4.19 but file_user_inode() was not added until v6.8 and never
back-ported to stable kernels. FMODE_BACKING that it depends on was added
in v6.5. This issue has gone largely unnoticed, so back-porting before
v6.8 is probably not worth it, so put 6.8 as the stable kernel prerequisite
version, although in practice the next long term kernel is 6.12.
Closes: https://lore.kernel.org/linux-perf-users/aBCwoq7w8ohBRQCh@fremen.lan
Reported-by: Edd Barrett <edd(a)theunixzoo.co.uk>
Signed-off-by: Adrian Hunter <adrian.hunter(a)intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
Acked-by: Amir Goldstein <amir73il(a)gmail.com>
Cc: stable(a)vger.kernel.org # 6.8
---
kernel/events/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 7541f6f..cd63ec8 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9492,7 +9492,7 @@ static bool perf_addr_filter_match(struct perf_addr_filter *filter,
if (!filter->path.dentry)
return false;
- if (d_inode(filter->path.dentry) != file_inode(file))
+ if (d_inode(filter->path.dentry) != file_user_inode(file))
return false;
if (filter->offset > offset + size)
The following commit has been merged into the perf/urgent branch of tip:
Commit-ID: 8818f507a9391019a3ec7c57b1a32e4b386e48a5
Gitweb: https://git.kernel.org/tip/8818f507a9391019a3ec7c57b1a32e4b386e48a5
Author: Adrian Hunter <adrian.hunter(a)intel.com>
AuthorDate: Mon, 13 Oct 2025 10:22:43 +03:00
Committer: Peter Zijlstra <peterz(a)infradead.org>
CommitterDate: Tue, 14 Oct 2025 10:38:09 +02:00
perf/core: Fix MMAP event path names with backing files
Some file systems like FUSE-based ones or overlayfs may record the backing
file in struct vm_area_struct vm_file, instead of the user file that the
user mmapped.
Since commit def3ae83da02f ("fs: store real path instead of fake path in
backing file f_path"), file_path() no longer returns the user file path
when applied to a backing file. There is an existing helper
file_user_path() for that situation.
Use file_user_path() instead of file_path() to get the path for MMAP
and MMAP2 events.
Example:
Setup:
# cd /root
# mkdir test ; cd test ; mkdir lower upper work merged
# cp `which cat` lower
# mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged
# perf record -e intel_pt//u -- /root/test/merged/cat /proc/self/maps
...
55b0ba399000-55b0ba434000 r-xp 00018000 00:1a 3419 /root/test/merged/cat
...
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.060 MB perf.data ]
#
Before:
File name is wrong (/cat), so decoding fails:
# perf script --no-itrace --show-mmap-events
cat 367 [016] 100.491492: PERF_RECORD_MMAP2 367/367: [0x55b0ba399000(0x9b000) @ 0x18000 00:02 3419 489959280]: r-xp /cat
...
# perf script --itrace=e | wc -l
Warning:
19 instruction trace errors
19
#
After:
File name is correct (/root/test/merged/cat), so decoding is ok:
# perf script --no-itrace --show-mmap-events
cat 364 [016] 72.153006: PERF_RECORD_MMAP2 364/364: [0x55ce4003d000(0x9b000) @ 0x18000 00:02 3419 3132534314]: r-xp /root/test/merged/cat
# perf script --itrace=e
# perf script --itrace=e | wc -l
0
#
Fixes: def3ae83da02f ("fs: store real path instead of fake path in backing file f_path")
Signed-off-by: Adrian Hunter <adrian.hunter(a)intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
Acked-by: Amir Goldstein <amir73il(a)gmail.com>
Cc: stable(a)vger.kernel.org
---
kernel/events/core.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index cd63ec8..7b5c237 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9416,7 +9416,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
* need to add enough zero bytes after the string to handle
* the 64bit alignment we do later.
*/
- name = file_path(file, buf, PATH_MAX - sizeof(u64));
+ name = d_path(file_user_path(file), buf, PATH_MAX - sizeof(u64));
if (IS_ERR(name)) {
name = "//toolong";
goto cpy_name;
The following commit has been merged into the perf/urgent branch of tip:
Commit-ID: fa4f4bae893fbce8a3edfff1ab7ece0c01dc1328
Gitweb: https://git.kernel.org/tip/fa4f4bae893fbce8a3edfff1ab7ece0c01dc1328
Author: Adrian Hunter <adrian.hunter(a)intel.com>
AuthorDate: Mon, 13 Oct 2025 10:22:44 +03:00
Committer: Peter Zijlstra <peterz(a)infradead.org>
CommitterDate: Tue, 14 Oct 2025 10:38:10 +02:00
perf/core: Fix MMAP2 event device with backing files
Some file systems like FUSE-based ones or overlayfs may record the backing
file in struct vm_area_struct vm_file, instead of the user file that the
user mmapped.
That causes perf to misreport the device major/minor numbers of the file
system of the file, and the generation of the file, and potentially other
inode details. There is an existing helper file_user_inode() for that
situation.
Use file_user_inode() instead of file_inode() to get the inode for MMAP2
events.
Example:
Setup:
# cd /root
# mkdir test ; cd test ; mkdir lower upper work merged
# cp `which cat` lower
# mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged
# perf record -e cycles:u -- /root/test/merged/cat /proc/self/maps
...
55b2c91d0000-55b2c926b000 r-xp 00018000 00:1a 3419 /root/test/merged/cat
...
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.004 MB perf.data (5 samples) ]
#
# stat /root/test/merged/cat
File: /root/test/merged/cat
Size: 1127792 Blocks: 2208 IO Block: 4096 regular file
Device: 0,26 Inode: 3419 Links: 1
Access: (0755/-rwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2025-09-08 12:23:59.453309624 +0000
Modify: 2025-09-08 12:23:59.454309624 +0000
Change: 2025-09-08 12:23:59.454309624 +0000
Birth: 2025-09-08 12:23:59.453309624 +0000
Before:
Device reported 00:02 differs from stat output and /proc/self/maps
# perf script --show-mmap-events | grep /root/test/merged/cat
cat 377 [-01] 243.078558: PERF_RECORD_MMAP2 377/377: [0x55b2c91d0000(0x9b000) @ 0x18000 00:02 3419 2068525940]: r-xp /root/test/merged/cat
After:
Device reported 00:1a is the same as stat output and /proc/self/maps
# perf script --show-mmap-events | grep /root/test/merged/cat
cat 362 [-01] 127.755167: PERF_RECORD_MMAP2 362/362: [0x55ba6e781000(0x9b000) @ 0x18000 00:1a 3419 0]: r-xp /root/test/merged/cat
With respect to stable kernels, overlayfs mmap function ovl_mmap() was
added in v4.19 but file_user_inode() was not added until v6.8 and never
back-ported to stable kernels. FMODE_BACKING that it depends on was added
in v6.5. This issue has gone largely unnoticed, so back-porting before
v6.8 is probably not worth it, so put 6.8 as the stable kernel prerequisite
version, although in practice the next long term kernel is 6.12.
Signed-off-by: Adrian Hunter <adrian.hunter(a)intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org>
Acked-by: Amir Goldstein <amir73il(a)gmail.com>
Cc: stable(a)vger.kernel.org # 6.8
---
kernel/events/core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 7b5c237..177e57c 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -9403,7 +9403,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
flags |= MAP_HUGETLB;
if (file) {
- struct inode *inode;
+ const struct inode *inode;
dev_t dev;
buf = kmalloc(PATH_MAX, GFP_KERNEL);
@@ -9421,7 +9421,7 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
name = "//toolong";
goto cpy_name;
}
- inode = file_inode(vma->vm_file);
+ inode = file_user_inode(vma->vm_file);
dev = inode->i_sb->s_dev;
ino = inode->i_ino;
gen = inode->i_generation;
We found some discrete AMD graphics devices hide funtion 0 and the whole
is not supposed to be probed.
Since our original purpose is to allow integrated devices (on bus 0) to
be probed without function 0, we can limit the islolated function probing
only on bus 0.
Cc: stable(a)vger.kernel.org
Fixes: a02fd05661d73a8 ("PCI: Extend isolated function probing to LoongArch")
Signed-off-by: Huacai Chen <chenhuacai(a)loongson.cn>
---
drivers/pci/probe.c | 2 +-
include/linux/hypervisor.h | 8 +++++---
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index c83e75a0ec12..da6a2aef823a 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2883,7 +2883,7 @@ int pci_scan_slot(struct pci_bus *bus, int devfn)
* a hypervisor that passes through individual PCI
* functions.
*/
- if (!hypervisor_isolated_pci_functions())
+ if (!hypervisor_isolated_pci_functions(bus->number))
break;
}
fn = next_fn(bus, dev, fn);
diff --git a/include/linux/hypervisor.h b/include/linux/hypervisor.h
index be5417303ecf..30ece04a16d9 100644
--- a/include/linux/hypervisor.h
+++ b/include/linux/hypervisor.h
@@ -32,13 +32,15 @@ static inline bool jailhouse_paravirt(void)
#endif /* !CONFIG_X86 */
-static inline bool hypervisor_isolated_pci_functions(void)
+static inline bool hypervisor_isolated_pci_functions(int bus)
{
if (IS_ENABLED(CONFIG_S390))
return true;
- if (IS_ENABLED(CONFIG_LOONGARCH))
- return true;
+ if (IS_ENABLED(CONFIG_LOONGARCH)) {
+ if (bus == 0)
+ return true;
+ }
return jailhouse_paravirt();
}
--
2.47.3