diff options
Diffstat (limited to 'freed-ora/current/f13/agp-fix-oom-and-buffer-overflow.patch')
| -rw-r--r-- | freed-ora/current/f13/agp-fix-oom-and-buffer-overflow.patch | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/freed-ora/current/f13/agp-fix-oom-and-buffer-overflow.patch b/freed-ora/current/f13/agp-fix-oom-and-buffer-overflow.patch new file mode 100644 index 000000000..7ca5956e2 --- /dev/null +++ b/freed-ora/current/f13/agp-fix-oom-and-buffer-overflow.patch @@ -0,0 +1,56 @@ +From: Vasiliy Kulikov <segoon@openwall.com> +Date: Thu, 14 Apr 2011 16:55:19 +0000 (+0400) +Subject: agp: fix OOM and buffer overflow +X-Git-Tag: v2.6.39-rc5~29^2~1 +X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=b522f02184b413955f3bc952e3776ce41edc6355 + +agp: fix OOM and buffer overflow + +page_count is copied from userspace. agp_allocate_memory() tries to +check whether this number is too big, but doesn't take into account the +wrap case. Also agp_create_user_memory() doesn't check whether +alloc_size is calculated from num_agp_pages variable without overflow. +This may lead to allocation of too small buffer with following buffer +overflow. + +Another problem in agp code is not addressed in the patch - kernel memory +exhaustion (AGPIOC_RESERVE and AGPIOC_ALLOCATE ioctls). It is not checked +whether requested pid is a pid of the caller (no check in agpioc_reserve_wrap()). +Each allocation is limited to 16KB, though, there is no per-process limit. +This might lead to OOM situation, which is not even solved in case of the +caller death by OOM killer - the memory is allocated for another (faked) process. + +Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> +Signed-off-by: Dave Airlie <airlied@redhat.com> +--- + +diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c +index 012cba0..850a643 100644 +--- a/drivers/char/agp/generic.c ++++ b/drivers/char/agp/generic.c +@@ -115,6 +115,9 @@ static struct agp_memory *agp_create_user_memory(unsigned long num_agp_pages) + struct agp_memory *new; + unsigned long alloc_size = num_agp_pages*sizeof(struct page *); + ++ if (INT_MAX/sizeof(struct page *) < num_agp_pages) ++ return NULL; ++ + new = kzalloc(sizeof(struct agp_memory), GFP_KERNEL); + if (new == NULL) + return NULL; +@@ -234,11 +237,14 @@ struct agp_memory *agp_allocate_memory(struct agp_bridge_data *bridge, + int scratch_pages; + struct agp_memory *new; + size_t i; ++ int cur_memory; + + if (!bridge) + return NULL; + +- if ((atomic_read(&bridge->current_memory_agp) + page_count) > bridge->max_memory_agp) ++ cur_memory = atomic_read(&bridge->current_memory_agp); ++ if ((cur_memory + page_count > bridge->max_memory_agp) || ++ (cur_memory + page_count < page_count)) + return NULL; + + if (type >= AGP_USER_TYPES) { |
