diff options
| author | Dan Rosenberg <drosenberg@vsecurity.com> | 2010-12-22 13:58:27 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-04-14 16:53:14 -0700 |
| commit | 69273e33a6d22d73dd89e4a68d54a0af3bd0e460 (patch) | |
| tree | 3b2c9f129f71e0ff07b0732e0846c0ceb7ac7287 | |
| parent | de00d49034d47ceaf4d44b6720b77deb40ca1692 (diff) | |
| download | lwn-69273e33a6d22d73dd89e4a68d54a0af3bd0e460.tar.gz lwn-69273e33a6d22d73dd89e4a68d54a0af3bd0e460.zip | |
irda: prevent integer underflow in IRLMP_ENUMDEVICES
commit fdac1e0697356ac212259f2147aa60c72e334861 upstream.
If the user-provided len is less than the expected offset, the
IRLMP_ENUMDEVICES getsockopt will do a copy_to_user() with a very large
size value. While this isn't be a security issue on x86 because it will
get caught by the access_ok() check, it may leak large amounts of kernel
heap on other architectures. In any event, this patch fixes it.
Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Moritz Muehlenhoff <jmm@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | net/irda/af_irda.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/net/irda/af_irda.c b/net/irda/af_irda.c index 10093aab6173..7313e1cc1e82 100644 --- a/net/irda/af_irda.c +++ b/net/irda/af_irda.c @@ -2277,6 +2277,14 @@ static int __irda_getsockopt(struct socket *sock, int level, int optname, switch (optname) { case IRLMP_ENUMDEVICES: + + /* Offset to first device entry */ + offset = sizeof(struct irda_device_list) - + sizeof(struct irda_device_info); + + if (len < offset) + return -EINVAL; + /* Ask lmp for the current discovery log */ discoveries = irlmp_get_discoveries(&list.len, self->mask.word, self->nslots); @@ -2286,15 +2294,9 @@ static int __irda_getsockopt(struct socket *sock, int level, int optname, err = 0; /* Write total list length back to client */ - if (copy_to_user(optval, &list, - sizeof(struct irda_device_list) - - sizeof(struct irda_device_info))) + if (copy_to_user(optval, &list, offset)) err = -EFAULT; - /* Offset to first device entry */ - offset = sizeof(struct irda_device_list) - - sizeof(struct irda_device_info); - /* Copy the list itself - watch for overflow */ if(list.len > 2048) { |