Messages in this thread Patch in this message | | | Date | Fri, 29 Oct 2010 16:10:26 +0200 (CEST) | From | Jesper Juhl <> | Subject | [PATCH] mac80211 failure to check kmalloc return value in key_key_read could lead to unpleasant surprises |
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I noticed two small issues in mac80211/debugfs_key.c::key_key_read while reading through the code. Patch below.
The key_key_read() function returns ssize_t and the value that's actually returned is the return value of simple_read_from_buffer() which also returns ssize_t, so let's hold the return value in a ssize_t local variable rather than a int one.
Also, memory is allocated dynamically with kmalloc() which can fail, but the return value of kmalloc() is not checked, so we may end up operating on a null pointer further on. So check for a NULL return and bail out with -ENOMEM in that case.
Please keep me on CC on replies since I'm not subscribed to linux-wireless.
Signed-off-by: Jesper Juhl <jj@chaosbits.net> --- debugfs_key.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/net/mac80211/debugfs_key.c b/net/mac80211/debugfs_key.c index 4aa47d0..1243d1d 100644 --- a/net/mac80211/debugfs_key.c +++ b/net/mac80211/debugfs_key.c @@ -203,9 +203,13 @@ static ssize_t key_key_read(struct file *file, char __user *userbuf, size_t count, loff_t *ppos) { struct ieee80211_key *key = file->private_data; - int i, res, bufsize = 2 * key->conf.keylen + 2; + int i, bufsize = 2 * key->conf.keylen + 2; char *buf = kmalloc(bufsize, GFP_KERNEL); char *p = buf; + ssize_t res; + + if (!buf) + return -ENOMEM; for (i = 0; i < key->conf.keylen; i++) p += scnprintf(p, bufsize + buf - p, "%02x", key->conf.key[i]);
-- Jesper Juhl <jj@chaosbits.net> http://www.chaosbits.net/ Plain text mails only, please http://www.expita.com/nomime.html Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html
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