Am Sun, 24 Aug 2025 11:00:55 +0200 schrieb Petr Vaněk <pv@xxxxxxxxxx>: > On Thu, Aug 21, 2025 at 06:58:06PM +0800, wangzijie wrote: > > To avoid potential UAF issues during module removal races, we use > > pde_set_flags() to save proc_ops flags in PDE itself before > > proc_register(), and then use pde_has_proc_*() helpers instead of > > directly dereferencing pde->proc_ops->*. > > > > However, the pde_set_flags() call was missing when creating net > > related proc files. This omission caused incorrect behavior which > > FMODE_LSEEK was being cleared inappropriately in proc_reg_open() > > for net proc files. Lars reported it in this link[1]. > > > > Fix this by ensuring pde_set_flags() is called when register proc > > entry, and add NULL check for proc_ops in pde_set_flags(). > > > > [1]: > > https://lore.kernel.org/all/20250815195616.64497967@xxxxxxxxxxxxxxxxxxxxx/ > > > > Fixes: ff7ec8dc1b64 ("proc: use the same treatment to check > > proc_lseek as ones for proc_read_iter et.al") Cc: > > stable@xxxxxxxxxxxxxxx Reported-by: Lars Wendler > > <polynomial-c@xxxxxx> Signed-off-by: wangzijie > > <wangzijie1@xxxxxxxxx> > > Tested-by: Petr Vaněk <pv@xxxxxxxxxx> > > We have noticed lseek issue with /proc/self/net/sockstat file recently > and this patch fixes it for us. > > Thanks, > Petr Applied to linux-6.12.43 and it fixes the issue in linux-6.12.y branch. I have yet to test it in linux-6.6.y branch. Tested by: Lars Wendler <polynomial-c@xxxxxx> Thanks Lars
