diff options
| author | Zijun Hu <[email protected]> | 2024-05-30 13:14:37 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <[email protected]> | 2024-06-12 11:24:05 +0000 |
| commit | dd6e9894b451e7c85cceb8e9dc5432679a70e7dc (patch) | |
| tree | a4138835436a937aac882865cd96cfe89f148512 | |
| parent | drivers: arch_topology: use __free attribute instead of of_node_put() (diff) | |
| download | kernel-dd6e9894b451e7c85cceb8e9dc5432679a70e7dc.tar.gz kernel-dd6e9894b451e7c85cceb8e9dc5432679a70e7dc.zip | |
kobject_uevent: Fix OOB access within zap_modalias_env()
zap_modalias_env() wrongly calculates size of memory block to move, so
will cause OOB memory access issue if variable MODALIAS is not the last
one within its @env parameter, fixed by correcting size to memmove.
Fixes: 9b3fa47d4a76 ("kobject: fix suppressing modalias in uevents delivered over netlink")
Cc: [email protected]
Signed-off-by: Zijun Hu <[email protected]>
Reviewed-by: Lk Sii <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
| -rw-r--r-- | lib/kobject_uevent.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 03b427e2707e..b7f2fa08d9c8 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -433,8 +433,23 @@ static void zap_modalias_env(struct kobj_uevent_env *env) len = strlen(env->envp[i]) + 1; if (i != env->envp_idx - 1) { + /* @env->envp[] contains pointers to @env->buf[] + * with @env->buflen chars, and we are removing + * variable MODALIAS here pointed by @env->envp[i] + * with length @len as shown below: + * + * 0 @env->buf[] @env->buflen + * --------------------------------------------- + * ^ ^ ^ ^ + * | |-> @len <-| target block | + * @env->envp[0] @env->envp[i] @env->envp[i + 1] + * + * so the "target block" indicated above is moved + * backward by @len, and its right size is + * @env->buflen - (@env->envp[i + 1] - @env->envp[0]). + */ memmove(env->envp[i], env->envp[i + 1], - env->buflen - len); + env->buflen - (env->envp[i + 1] - env->envp[0])); for (j = i; j < env->envp_idx - 1; j++) env->envp[j] = env->envp[j + 1] - len; |