The patch titled
drivers/char/agp/generic.c: fix OOM and buffer overflow
has been removed from the -mm tree. Its filename was
drivers-char-agp-genericc-fix-oom-and-buffer-overflow.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: drivers/char/agp/generic.c: fix OOM and buffer overflow
From: Vasiliy Kulikov <segoon@xxxxxxxxxxxx>
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@xxxxxxxxxxxx>
Cc: Dave Airlie <airlied@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/char/agp/generic.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff -puN drivers/char/agp/generic.c~drivers-char-agp-genericc-fix-oom-and-buffer-overflow drivers/char/agp/generic.c
--- a/drivers/char/agp/generic.c~drivers-char-agp-genericc-fix-oom-and-buffer-overflow
+++ a/drivers/char/agp/generic.c
@@ -115,6 +115,9 @@ static struct agp_memory *agp_create_use
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(s
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) {
_
Patches currently in -mm which might be from segoon@xxxxxxxxxxxx are
origin.patch
arch-arm-mach-ux500-mbox-db5500c-world-writable-sysfs-fifo-file.patch
aic94xx-world-writable-sysfs-update_bios-file.patch
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