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authorDominique Martinet <dominique.martinet@cea.fr>2018-08-28 01:32:35 +0300
committerDominique Martinet <dominique.martinet@cea.fr>2018-08-29 07:39:57 +0300
commit62e3941776fea8678bb8120607039410b1b61a65 (patch)
tree86f8c7de4bb26bf1aeb522e9c93732a6835e0fe0
parent81c99089bce693b94b775b6eb888115d2d540086 (diff)
downloadlinux-62e3941776fea8678bb8120607039410b1b61a65.tar.xz
9p: clear dangling pointers in p9stat_free
p9stat_free is more of a cleanup function than a 'free' function as it only frees the content of the struct; there are chances of use-after-free if it is improperly used (e.g. p9stat_free called twice as it used to be possible to) Clearing dangling pointers makes the function idempotent and safer to use. Link: http://lkml.kernel.org/r/1535410108-20650-2-git-send-email-asmadeus@codewreck.org Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr> Reported-by: syzbot+d4252148d198410b864f@syzkaller.appspotmail.com
-rw-r--r--net/9p/protocol.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/net/9p/protocol.c b/net/9p/protocol.c
index 4a1e1dd30b52..ee32bbf12675 100644
--- a/net/9p/protocol.c
+++ b/net/9p/protocol.c
@@ -46,10 +46,15 @@ p9pdu_writef(struct p9_fcall *pdu, int proto_version, const char *fmt, ...);
void p9stat_free(struct p9_wstat *stbuf)
{
kfree(stbuf->name);
+ stbuf->name = NULL;
kfree(stbuf->uid);
+ stbuf->uid = NULL;
kfree(stbuf->gid);
+ stbuf->gid = NULL;
kfree(stbuf->muid);
+ stbuf->muid = NULL;
kfree(stbuf->extension);
+ stbuf->extension = NULL;
}
EXPORT_SYMBOL(p9stat_free);