[PATCH] Fix the kernel panic of audit_filter_task when AUDIT_PERM or
AUDIT_FILETYPE field is set
When calling audit_filter_task(), it calls audit_filter_rules() with
audit_context is NULL.
If the AUDIT_PERM or AUDIT_FILETYPE field is set, audit_match_perm() or
audit_match_filetype() will use ctx->xx.
But the ctx is NULL in this condition, so kernel will panic.
Signed-off-by: Zhang Xiliang <[EMAIL PROTECTED]>
---
kernel/auditsc.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 012c94e..29b6964 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -243,6 +243,8 @@ static inline int open_arg(int flags, int mask)
static int audit_match_perm(struct audit_context *ctx, int mask)
{
+ if(!ctx)
+ return 0;
unsigned n = ctx->major;
switch (audit_classify_syscall(ctx->arch, n)) {
case 0: /* native */
@@ -284,6 +286,8 @@ static int audit_match_filetype(struct audit_context *ctx,
int which)
{
unsigned index = which & ~S_IFMT;
mode_t mode = which & S_IFMT;
+ if(!ctx)
+ return 0;
if (index >= ctx->name_count)
return 0;
if (ctx->names[index].ino == -1)
zhangxiliang said the following on 2008-08-01 19:15:
> When calling audit_filter_task(), it calls audit_filter_rules() with
> audit_context is NULL.
> If the key field is set, the result in audit_filter_rules() will be set to 1
> and
> ctx->filterkey will be set to key.
> But the ctx is NULL in this condition, so kernel will panic.
>
> Signed-off-by: Zhang Xiliang <[EMAIL PROTECTED]>
> ---
> kernel/auditsc.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 4699950..012c94e 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -610,7 +610,7 @@ static int audit_filter_rules(struct task_struct *tsk,
> if (!result)
> return 0;
> }
> - if (rule->filterkey)
> + if (rule->filterkey && ctx)
> ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC);
> switch (rule->action) {
> case AUDIT_NEVER: *state = AUDIT_DISABLED; break;
>
> --
> Linux-audit mailing list
> [email protected]
> https://www.redhat.com/mailman/listinfo/linux-audit
>
>
>
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