phonet: pep: do not write beyond optlen in getsockopt

Browse source

pep_getsockopt() clamps the reported length to the caller's buffer with
min_t(), but then stores the value with put_user(val, (int __user *)
optval), which always writes sizeof(int) bytes. A getsockopt() call with
an optlen smaller than sizeof(int) thus reports the clamped length yet
writes a full int, one to three bytes past the user buffer.

Write the value with copy_to_user() bounded by len, so at most optlen
bytes are copied, matching the length reported back to userspace.

Fixes: 02a47617cd ("Phonet: implement GPRS virtual interface over PEP socket")
Acked-by: Rémi Denis-Courmont <remi@remlab.net>
Reviewed-by: Joe Damato <joe@dama.to>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260729-getsockopt_phase4-v4-4-c44576757c17@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

...

This commit is contained in:

Breno Leitao 2026-07-29 02:29:47 -07:00 • committed by Jakub Kicinski

parent 6cd4e6c044

commit 77e5eb0e19

1 changed files with 1 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

2

net/phonet/pep.c

View file