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| author | Dominique Martinet <dominique.martinet@cea.fr> | 2018-08-28 00:32:35 +0200 |
|---|---|---|
| committer | Dominique Martinet <dominique.martinet@cea.fr> | 2018-08-29 06:39:57 +0200 |
| commit | 62e3941776fea8678bb8120607039410b1b61a65 (patch) | |
| tree | 86f8c7de4bb26bf1aeb522e9c93732a6835e0fe0 /net/9p | |
| parent | v9fs_dir_readdir: fix double-free on p9stat_read error (diff) | |
| download | linux-62e3941776fea8678bb8120607039410b1b61a65.tar.xz linux-62e3941776fea8678bb8120607039410b1b61a65.zip | |
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
Diffstat (limited to 'net/9p')
| -rw-r--r-- | net/9p/protocol.c | 5 |
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); |