CVE-2025-71117

In the Linux kernel, the following vulnerability has been resolved:

block: Remove queue freezing from several sysfs store callbacks

Freezing the request queue from inside sysfs store callbacks may cause a deadlock in combination with the dm-multipath driver and the queueifno_path option. Additionally, freezing the request queue slows down system boot on systems where sysfs attributes are set synchronously.

Fix this by removing the blkmqfreezequeue() / blkmqunfreezequeue() calls from the store callbacks that do not strictly need these callbacks. Add the __dataracy annotation to requestqueue.rqtimeout to suppress KCSAN data race reports about the rqtimeout reads.

This patch may cause a small delay in applying the new settings.

For all the attributes affected by this patch, I/O will complete correctly whether the old or the new value of the attribute is used.

This patch affects the following sysfs attributes: * iopolldelay * iotimeout * nomerges * readaheadkb * rqaffinity

Here is an example of a deadlock triggered by running test srp/002 if this patch is not applied:

task:multipathd Call Trace: <TASK> __schedule+0x8c1/0x1bf0 schedule+0xdd/0x270 schedulepreemptdisabled+0x1c/0x30 __mutexlock+0xb89/0x1650 mutexlocknested+0x1f/0x30 dmtablesetrestrictions+0x823/0xdf0 __bind+0x166/0x590 dmswaptable+0x2a7/0x490 do_resume+0x1b1/0x610 devsuspend+0x55/0x1a0 ctlioctl+0x3a5/0x7e0 dmctlioctl+0x12/0x20 __x64sysioctl+0x127/0x1a0 x64syscall+0xe2b/0x17d0 dosyscall64+0x96/0x3a0 entrySYSCALL64afterhwframe+0x4b/0x53 </TASK> task:(udev-worker) Call Trace: <TASK> __schedule+0x8c1/0x1bf0 schedule+0xdd/0x270 blkmqfreezequeuewait+0xf2/0x140 blkmqfreezequeuenomemsave+0x23/0x30 queuerastore+0x14e/0x290 queueattrstore+0x23e/0x2c0 sysfskfwrite+0xde/0x140 kernfsfopwriteiter+0x3b2/0x630 vfswrite+0x4fd/0x1390 ksys_write+0xfd/0x230 __x64syswrite+0x76/0xc0 x64syscall+0x276/0x17d0 dosyscall64+0x96/0x3a0 entrySYSCALL64afterhwframe+0x4b/0x53 </TASK>