From baf76f0c58aec435a3a864075b8f6d8ee5d1f17e Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Thu, 25 Apr 2019 16:13:58 -0700
Subject: [PATCH] slip: make slhc_free() silently accept an error pointer
Git-commit: baf76f0c58aec435a3a864075b8f6d8ee5d1f17e
Patch-mainline: v5.1-rc7
References: bsc#1051510
This way, slhc_free() accepts what slhc_init() returns, whether that is
an error or not.
In particular, the pattern in sl_alloc_bufs() is
slcomp = slhc_init(16, 16);
...
slhc_free(slcomp);
for the error handling path, and rather than complicate that code, just
make it ok to always free what was returned by the init function.
That's what the code used to do before commit 4ab42d78e37a ("ppp, slip:
Validate VJ compression slot parameters completely") when slhc_init()
just returned NULL for the error case, with no actual indication of the
details of the error.
Reported-by: syzbot+45474c076a4927533d2e@syzkaller.appspotmail.com
Fixes: 4ab42d78e37a ("ppp, slip: Validate VJ compression slot parameters completely")
Acked-by: Ben Hutchings <ben@decadent.org.uk>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/net/slip/slhc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/slip/slhc.c b/drivers/net/slip/slhc.c
index f4e93f5fc204..ea90db3c7705 100644
--- a/drivers/net/slip/slhc.c
+++ b/drivers/net/slip/slhc.c
@@ -153,7 +153,7 @@ slhc_init(int rslots, int tslots)
void
slhc_free(struct slcompress *comp)
{
- if ( comp == NULLSLCOMPR )
+ if ( IS_ERR_OR_NULL(comp) )
return;
if ( comp->tstate != NULLSLSTATE )
--
2.16.4