2022-06-15 15:47:22

by Christian Göttsche

Subject: [PATCH] audit: free module name

Reset the type of the record last as the helper `audit_free_module()`
depends on it.

unreferenced object 0xffff888153b707f0 (size 16):
comm "modprobe", pid 1319, jiffies 4295110033 (age 1083.016s)
hex dump (first 16 bytes):
62 69 6e 66 6d 74 5f 6d 69 73 63 00 6b 6b 6b a5 binfmt_misc.kkk.
backtrace:
[<ffffffffa07dbf9b>] kstrdup+0x2b/0x50
[<ffffffffa04b0a9d>] __audit_log_kern_module+0x4d/0xf0
[<ffffffffa03b6664>] load_module+0x9d4/0x2e10
[<ffffffffa03b8f44>] __do_sys_finit_module+0x114/0x1b0
[<ffffffffa1f47124>] do_syscall_64+0x34/0x80
[<ffffffffa200007e>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

Fixes: 12c5e81d3fd0 ("audit: prepare audit_context for use in calling contexts beyond syscalls")
Signed-off-by: Christian Göttsche <[email protected]>
---
kernel/auditsc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index f3a2abd6d1a1..3a8c9d744800 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1014,10 +1014,10 @@ static void audit_reset_context(struct audit_context *ctx)
ctx->target_comm[0] = '\0';
unroll_tree_refs(ctx, NULL, 0);
WARN_ON(!list_empty(&ctx->killed_trees));
- ctx->type = 0;
audit_free_module(ctx);
ctx->fds[0] = -1;
audit_proctitle_free(ctx);
+ ctx->type = 0; /* reset last for audit_free_*() */
}

static inline struct audit_context *audit_alloc_context(enum audit_state state)
--
2.36.1

2022-06-16 00:09:49

by Paul Moore

Subject: Re: [PATCH] audit: free module name

On Wed, Jun 15, 2022 at 11:44 AM Christian Göttsche
<[email protected]> wrote:
>
> Reset the type of the record last as the helper `audit_free_module()`
> depends on it.
>
> unreferenced object 0xffff888153b707f0 (size 16):
> comm "modprobe", pid 1319, jiffies 4295110033 (age 1083.016s)
> hex dump (first 16 bytes):
> 62 69 6e 66 6d 74 5f 6d 69 73 63 00 6b 6b 6b a5 binfmt_misc.kkk.
> backtrace:
> [<ffffffffa07dbf9b>] kstrdup+0x2b/0x50
> [<ffffffffa04b0a9d>] __audit_log_kern_module+0x4d/0xf0
> [<ffffffffa03b6664>] load_module+0x9d4/0x2e10
> [<ffffffffa03b8f44>] __do_sys_finit_module+0x114/0x1b0
> [<ffffffffa1f47124>] do_syscall_64+0x34/0x80
> [<ffffffffa200007e>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
>
> Fixes: 12c5e81d3fd0 ("audit: prepare audit_context for use in calling contexts beyond syscalls")
> Signed-off-by: Christian Göttsche <[email protected]>
> ---
> kernel/auditsc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

Thanks Christian, I just merged this into audit/stable-5.19 and I'll
send this up to Linus as soon as the automated tests finish their
runs.

--
paul-moore.com