diff options
| author | Dan Rosenberg <drosenberg@vsecurity.com> | 2010-12-22 18:58:27 -0500 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2012-04-09 14:19:45 +0200 |
| commit | a61eed7f742c596ad18f423be576563ac9d59c11 (patch) | |
| tree | 6598fa2d6fa2557d4892d7c02dfb319970cdd190 | |
| parent | 632faa2d548dabaf55ac0bfcb21599da946f9936 (diff) | |
| download | linux-2.4-a61eed7f742c596ad18f423be576563ac9d59c11.tar.gz | |
irda: prevent integer underflow in IRLMP_ENUMDEVICES
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>
Cc: stable <stable@kernel.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -rw-r--r-- | net/irda/af_irda.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/net/irda/af_irda.c b/net/irda/af_irda.c index 3d198b1f7dea6c..a029801e997516 100644 --- a/net/irda/af_irda.c +++ b/net/irda/af_irda.c @@ -2154,6 +2154,16 @@ 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) { + err = -EINVAL; + goto out; + } + /* Ask lmp for the current discovery log */ discoveries = irlmp_get_discoveries(&list.len, self->mask, self->nslots); @@ -2163,15 +2173,9 @@ 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) { |