cbcvebase.
CVE-2025-40305
published 2025-12-08

CVE-2025-40305: In the Linux kernel, the following vulnerability has been resolved: 9p/trans_fd: p9_fd_request: kick rx thread if EPOLLIN p9_read_work() doesn't set Rworksched…

PriorityP422high7.8
EPSS
0.17%
6.6th percentile
In the Linux kernel, the following vulnerability has been resolved: 9p/trans_fd: p9_fd_request: kick rx thread if EPOLLIN p9_read_work() doesn't set Rworksched and doesn't do schedule_work(m->rq) if list_empty(&m->req_list). However, if the pipe is full, we need to read more data and this used to work prior to commit aaec5a95d59615 ("pipe_read: don't wake up the writer if the pipe is still full"). p9_read_work() does p9_fd_read() -> ... -> anon_pipe_read() which (before the commit above) triggered the unnecessary wakeup. This wakeup calls p9_pollwake() which kicks p9_poll_workfn() -> p9_poll_mux(), p9_poll_mux() will notice EPOLLIN and schedule_work(&m->rq). This no longer happens after the optimization above, change p9_fd_request() to use p9_poll_mux() instead of only checking for EPOLLOUT.

Affected

13 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.17.8-1 (forky)linux 6.17.8-1 (forky)
linuxlinux
linuxlinux>= aaec5a95d59615523db03dd53c2052f0a87beea7 < 242531004d7de8c159f9bfadebe33fe8060b1046242531004d7de8c159f9bfadebe33fe8060b1046
linuxlinux>= aaec5a95d59615523db03dd53c2052f0a87beea7 < e8fe3f07a357c39d429e02ca34f740692d88967ae8fe3f07a357c39d429e02ca34f740692d88967a
linuxlinux_kernel>= 0 < 6.17.8-16.17.8-1
linuxlinux_kernel>= 0 < 6.8.0-106.1066.8.0-106.106
linuxlinux_kernel>= 0 < 6.17.0-14.146.17.0-14.14
linuxlinux_kernel>= 6.14.0 < 6.17.86.17.8
msrcazl3_indent_2.2.13-1_on_azure_linux_3.0
msrcazl3_kernel_6.6.117.1-1_on_azure_linux_3.0
ubuntulinux-aws
ubuntulinux-oracle
ubuntulinux-xilinx

CVSS provenance

vendor_ubuntu7.8HIGH
osv3.2LOW
vendor_msrc7.0HIGH
vendor_redhat5.5MEDIUM
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