diff options
| author | Takamitsu Iwai <takamitz@amazon.co.jp> | 2025-08-23 11:58:56 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-08-27 17:43:08 +0300 |
| commit | d860d1faa6b2ce3becfdb8b0c2b048ad31800061 (patch) | |
| tree | a27770249cfd5066696f5bc917acf37170a632d1 /include | |
| parent | dcb34659028f856c423a29ef9b4e2571d203444d (diff) | |
| download | linux-d860d1faa6b2ce3becfdb8b0c2b048ad31800061.tar.xz | |
net: rose: convert 'use' field to refcount_t
The 'use' field in struct rose_neigh is used as a reference counter but
lacks atomicity. This can lead to race conditions where a rose_neigh
structure is freed while still being referenced by other code paths.
For example, when rose_neigh->use becomes zero during an ioctl operation
via rose_rt_ioctl(), the structure may be removed while its timer is
still active, potentially causing use-after-free issues.
This patch changes the type of 'use' from unsigned short to refcount_t and
updates all code paths to use rose_neigh_hold() and rose_neigh_put() which
operate reference counts atomically.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Takamitsu Iwai <takamitz@amazon.co.jp>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250823085857.47674-3-takamitz@amazon.co.jp
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/rose.h | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/include/net/rose.h b/include/net/rose.h index 174b4f605d84..2b5491bbf39a 100644 --- a/include/net/rose.h +++ b/include/net/rose.h @@ -8,6 +8,7 @@ #ifndef _ROSE_H #define _ROSE_H +#include <linux/refcount.h> #include <linux/rose.h> #include <net/ax25.h> #include <net/sock.h> @@ -96,7 +97,7 @@ struct rose_neigh { ax25_cb *ax25; struct net_device *dev; unsigned short count; - unsigned short use; + refcount_t use; unsigned int number; char restarted; char dce_mode; @@ -151,12 +152,19 @@ struct rose_sock { #define rose_sk(sk) ((struct rose_sock *)(sk)) +static inline void rose_neigh_hold(struct rose_neigh *rose_neigh) +{ + refcount_inc(&rose_neigh->use); +} + static inline void rose_neigh_put(struct rose_neigh *rose_neigh) { - if (rose_neigh->ax25) - ax25_cb_put(rose_neigh->ax25); - kfree(rose_neigh->digipeat); - kfree(rose_neigh); + if (refcount_dec_and_test(&rose_neigh->use)) { + if (rose_neigh->ax25) + ax25_cb_put(rose_neigh->ax25); + kfree(rose_neigh->digipeat); + kfree(rose_neigh); + } } /* af_rose.c */ |