CVE-2025-38653

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

proc: use the same treatment to check proc_lseek as ones for proc_read_iter et.al

Check pde->proc_ops->proc_lseek directly may cause UAF in rmmod scenario. It's a gap in proc_reg_open() after commit 654b33ada4ab("proc: fix UAF in proc_get_inode()"). Followed by AI Viro's suggestion, fix it in same manner.

A race in procfs could dereference a freed proc_ops->proc_lseek pointer when a /proc file is opened while its backing module is being removed, leading to a kernel UAF and potential crash. The fix mirrors existing read/ioctl handling: it precomputes capability flags on entry creation and checks those flags (not the function pointer) in proc_reg_open(), eliminating the rmmod-time gap. This is primarily a local DoS: an unprivileged user can open/seek a proc entry while an administrator unloads the module.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.