From 9c8c39bae89ab3cd6133d244fa19ee2141aabeac Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Thu, 25 Apr 2019 16:13:58 -0700 Subject: [PATCH] slip: make slhc_free() silently accept an error pointer commit baf76f0c58aec435a3a864075b8f6d8ee5d1f17e upstream. 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 Cc: David Miller Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- 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 ) -- GitLab