[kernel/f13/master] AGP security fixes
Chuck Ebbert
cebbert at fedoraproject.org
Fri Apr 29 17:02:44 UTC 2011
commit 29f13318a318d666c4b93b513aa82aa1b9c0d634
Author: Chuck Ebbert <cebbert at redhat.com>
Date: Fri Apr 29 13:02:25 2011 -0400
AGP security fixes
agp: fix arbitrary kernel memory writes (CVE-2011-1745)
agp: fix OOM and buffer overflow (CVE-2011-1746)
agp-fix-arbitrary-kernel-memory-writes.patch | 55 +++++++++++++++++++++++++
agp-fix-oom-and-buffer-overflow.patch | 56 ++++++++++++++++++++++++++
kernel.spec | 12 ++++++
3 files changed, 123 insertions(+), 0 deletions(-)
---
diff --git a/agp-fix-arbitrary-kernel-memory-writes.patch b/agp-fix-arbitrary-kernel-memory-writes.patch
new file mode 100644
index 0000000..35d6d1a
--- /dev/null
+++ b/agp-fix-arbitrary-kernel-memory-writes.patch
@@ -0,0 +1,55 @@
+From: Vasiliy Kulikov <segoon at openwall.com>
+Date: Thu, 14 Apr 2011 16:55:16 +0000 (+0400)
+Subject: agp: fix arbitrary kernel memory writes
+X-Git-Tag: v2.6.39-rc5~29^2
+X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=194b3da873fd334ef183806db751473512af29ce
+
+agp: fix arbitrary kernel memory writes
+
+pg_start is copied from userspace on AGPIOC_BIND and AGPIOC_UNBIND ioctl
+cmds of agp_ioctl() and passed to agpioc_bind_wrap(). As said in the
+comment, (pg_start + mem->page_count) may wrap in case of AGPIOC_BIND,
+and it is not checked at all in case of AGPIOC_UNBIND. As a result, user
+with sufficient privileges (usually "video" group) may generate either
+local DoS or privilege escalation.
+
+Signed-off-by: Vasiliy Kulikov <segoon at openwall.com>
+Signed-off-by: Dave Airlie <airlied at redhat.com>
+---
+
+diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
+index 850a643..b072648 100644
+--- a/drivers/char/agp/generic.c
++++ b/drivers/char/agp/generic.c
+@@ -1095,8 +1095,8 @@ int agp_generic_insert_memory(struct agp_memory * mem, off_t pg_start, int type)
+ return -EINVAL;
+ }
+
+- /* AK: could wrap */
+- if ((pg_start + mem->page_count) > num_entries)
++ if (((pg_start + mem->page_count) > num_entries) ||
++ ((pg_start + mem->page_count) < pg_start))
+ return -EINVAL;
+
+ j = pg_start;
+@@ -1130,7 +1130,7 @@ int agp_generic_remove_memory(struct agp_memory *mem, off_t pg_start, int type)
+ {
+ size_t i;
+ struct agp_bridge_data *bridge;
+- int mask_type;
++ int mask_type, num_entries;
+
+ bridge = mem->bridge;
+ if (!bridge)
+@@ -1142,6 +1142,11 @@ int agp_generic_remove_memory(struct agp_memory *mem, off_t pg_start, int type)
+ if (type != mem->type)
+ return -EINVAL;
+
++ num_entries = agp_num_entries();
++ if (((pg_start + mem->page_count) > num_entries) ||
++ ((pg_start + mem->page_count) < pg_start))
++ return -EINVAL;
++
+ mask_type = bridge->driver->agp_type_to_mask_type(bridge, type);
+ if (mask_type != 0) {
+ /* The generic routines know nothing of memory types */
diff --git a/agp-fix-oom-and-buffer-overflow.patch b/agp-fix-oom-and-buffer-overflow.patch
new file mode 100644
index 0000000..7ca5956
--- /dev/null
+++ b/agp-fix-oom-and-buffer-overflow.patch
@@ -0,0 +1,56 @@
+From: Vasiliy Kulikov <segoon at 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 at openwall.com>
+Signed-off-by: Dave Airlie <airlied at 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) {
diff --git a/kernel.spec b/kernel.spec
index ee0302e..3cea8b8 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -851,6 +851,11 @@ Patch13955: virtio_net-add-schedule-check-to-napi_enable-call.patch
# cve-2011-1079
Patch13956: bluetooth-bnep-fix-buffer-overflow.patch
+# cve-2011-1745
+Patch13957: agp-fix-arbitrary-kernel-memory-writes.patch
+# cve-2011-1746
+Patch13958: agp-fix-oom-and-buffer-overflow.patch
+
%endif
BuildRoot: %{_tmppath}/kernel-%{KVERREL}-root
@@ -1611,6 +1616,11 @@ ApplyPatch virtio_net-add-schedule-check-to-napi_enable-call.patch
# cve-2011-1079
ApplyPatch bluetooth-bnep-fix-buffer-overflow.patch
+# cve-2011-1745
+ApplyPatch agp-fix-arbitrary-kernel-memory-writes.patch
+# cve-2011-1746
+ApplyPatch agp-fix-oom-and-buffer-overflow.patch
+
# END OF PATCH APPLICATIONS
%endif
@@ -2233,6 +2243,8 @@ fi
%changelog
* Fri Apr 29 2011 Chuck Ebbert <cebbert at redhat.com> 2.6.34.9-69
- Bluetooth: bnep: fix buffer overflow (CVE-2011-1079)
+- agp: fix arbitrary kernel memory writes (CVE-2011-1745)
+- agp: fix OOM and buffer overflow (CVE-2011-1746)
* Sun Apr 17 2011 Chuck Ebbert <cebbert at redhat.com>
- Linux 2.6.34.9
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