2013-05-30 10:20:42

by Vakul Garg

[permalink] [raw]
Subject: [PATCH] crypto: caam - Fixed the memory out of bound overwrite issue

When kernel is compiled with CONFIG_SLUB_DEBUG=y and
CRYPTO_MANAGER_DISABLE_TESTS=n, during kernel bootup, the kernel
reports error given below. The root cause is that in function
hash_digest_key(), for allocating descriptor, insufficient memory was
being allocated. The required number of descriptor words apart from
input and output pointers are 8 (instead of 6).

=============================================================================
BUG dma-kmalloc-32 (Not tainted): Redzone overwritten
-----------------------------------------------------------------------------

Disabling lock debugging due to kernel taint
INFO: 0xdec5dec0-0xdec5dec3. First byte 0x0 instead of 0xcc
INFO: Allocated in ahash_setkey+0x60/0x594 age=7 cpu=1 pid=1257
__kmalloc+0x154/0x1b4
ahash_setkey+0x60/0x594
test_hash+0x260/0x5a0
alg_test_hash+0x48/0xb0
alg_test+0x84/0x228
cryptomgr_test+0x4c/0x54
kthread+0x98/0x9c
ret_from_kernel_thread+0x64/0x6c
INFO: Slab 0xc0bd0ba0 objects=19 used=2 fp=0xdec5d0d0 flags=0x0081
INFO: Object 0xdec5dea0 @offset=3744 fp=0x5c200014

Bytes b4 dec5de90: 00 00 00 00 00 00 00 00 5a 5a 5a 5a 5a 5a 5a 5a
........ZZZZZZZZ
Object dec5dea0: b0 80 00 0a 84 41 00 0d f0 40 00 00 00 67 3f c0
[email protected]?.
Object dec5deb0: 00 00 00 50 2c 14 00 50 f8 40 00 00 1e c5 d0 00
...P,[email protected]
Redzone dec5dec0: 00 00 00 14 ....
Padding dec5df68: 5a 5a 5a 5a 5a 5a 5a 5a
ZZZZZZZZ
Call Trace:
[dec65b60] [c00071b4] show_stack+0x4c/0x168 (unreliable)
[dec65ba0] [c00d4ec8] check_bytes_and_report+0xe4/0x11c
[dec65bd0] [c00d507c] check_object+0x17c/0x23c
[dec65bf0] [c0550a00] free_debug_processing+0xf4/0x294
[dec65c20] [c0550bdc] __slab_free+0x3c/0x294
[dec65c80] [c03f0744] ahash_setkey+0x4e0/0x594
[dec65cd0] [c01ef138] test_hash+0x260/0x5a0
[dec65e50] [c01ef4c0] alg_test_hash+0x48/0xb0
[dec65e70] [c01eecc4] alg_test+0x84/0x228
[dec65ee0] [c01ec640] cryptomgr_test+0x4c/0x54
[dec65ef0] [c005adc0] kthread+0x98/0x9c
[dec65f40] [c000e1ac] ret_from_kernel_thread+0x64/0x6c
FIX dma-kmalloc-32: Restoring 0xdec5dec0-0xdec5dec3=0xcc

Change-Id: I0c7a1048053e811025d1c3b487940f87345c8f5d
Signed-off-by: Vakul Garg <[email protected]>
CC: <[email protected]> #3.9
Reviewed-by: Geanta Neag Horia Ioan-B05471 <[email protected]>
Reviewed-by: Fleming Andrew-AFLEMING <[email protected]>
Tested-by: Fleming Andrew-AFLEMING <[email protected]>
---
drivers/crypto/caam/caamhash.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/crypto/caam/caamhash.c b/drivers/crypto/caam/caamhash.c
index ae765ac..bf8c77c 100644
--- a/drivers/crypto/caam/caamhash.c
+++ b/drivers/crypto/caam/caamhash.c
@@ -427,7 +427,7 @@ static u32 hash_digest_key(struct caam_hash_ctx *ctx, const u8 *key_in,
dma_addr_t src_dma, dst_dma;
int ret = 0;

- desc = kmalloc(CAAM_CMD_SZ * 6 + CAAM_PTR_SZ * 2, GFP_KERNEL | GFP_DMA);
+ desc = kmalloc(CAAM_CMD_SZ * 8 + CAAM_PTR_SZ * 2, GFP_KERNEL | GFP_DMA);
if (!desc) {
dev_err(jrdev, "unable to allocate key input memory\n");
return -ENOMEM;
--
1.7.7.6