diff mbox series

[net-next,v2,1/6] tcp: fix incorrect parameter validation in the do_tcp_getsockopt() function

Message ID 20240307142030.2708698-2-Ilia.Gavrilov@infotecs.ru (mailing list archive)
State Accepted
Commit 716edc9706deb3bb2ff56e2eeb83559cea8f22db
Delegated to: Netdev Maintainers
Headers show
Series fix incorrect parameter validation in the *_get_sockopt() functions | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 942 this patch: 942
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 5 of 5 maintainers
netdev/build_clang success Errors and warnings before: 957 this patch: 957
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 958 this patch: 958
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 13 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-03-08--09-00 (tests: 890)

Commit Message

Gavrilov Ilia March 7, 2024, 2:23 p.m. UTC
The 'len' variable can't be negative when assigned the result of
'min_t' because all 'min_t' parameters are cast to unsigned int,
and then the minimum one is chosen.

To fix the logic, check 'len' as read from 'optlen',
where the types of relevant variables are (signed) int.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
---
V2:
 - reword the patch description

 net/ipv4/tcp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Jason Xing March 8, 2024, 3:43 a.m. UTC | #1
On Thu, Mar 7, 2024 at 10:44 PM Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru> wrote:
>
> The 'len' variable can't be negative when assigned the result of
> 'min_t' because all 'min_t' parameters are cast to unsigned int,
> and then the minimum one is chosen.
>
> To fix the logic, check 'len' as read from 'optlen',
> where the types of relevant variables are (signed) int.
>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>

For the patch itself, please feel free to add:
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>

I notice that you use Fixes meanwhile you target net-next. I'm not
sure if it's proper.

> ---
> V2:
>  - reword the patch description
>
>  net/ipv4/tcp.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
> index c82dc42f57c6..a4f418592314 100644
> --- a/net/ipv4/tcp.c
> +++ b/net/ipv4/tcp.c
> @@ -4010,11 +4010,11 @@ int do_tcp_getsockopt(struct sock *sk, int level,
>         if (copy_from_sockptr(&len, optlen, sizeof(int)))
>                 return -EFAULT;
>
> -       len = min_t(unsigned int, len, sizeof(int));
> -
>         if (len < 0)
>                 return -EINVAL;
>
> +       len = min_t(unsigned int, len, sizeof(int));
> +
>         switch (optname) {
>         case TCP_MAXSEG:
>                 val = tp->mss_cache;
> --
> 2.39.2
>
diff mbox series

Patch

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index c82dc42f57c6..a4f418592314 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -4010,11 +4010,11 @@  int do_tcp_getsockopt(struct sock *sk, int level,
 	if (copy_from_sockptr(&len, optlen, sizeof(int)))
 		return -EFAULT;
 
-	len = min_t(unsigned int, len, sizeof(int));
-
 	if (len < 0)
 		return -EINVAL;
 
+	len = min_t(unsigned int, len, sizeof(int));
+
 	switch (optname) {
 	case TCP_MAXSEG:
 		val = tp->mss_cache;