From: Dan Rosenberg <[email protected]> ------------------- This is a commit scheduled for the next v2.6.34 longterm release. If you see a problem with using this for longterm, please comment. -------------------
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 <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Paul Gortmaker <[email protected]> --- 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 6fae047..e63c226 100644 --- a/net/irda/af_irda.c +++ b/net/irda/af_irda.c @@ -2278,6 +2278,14 @@ 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); @@ -2287,15 +2295,9 @@ 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) { -- 1.7.4.4 _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
