This series fixes a use-after-free KASAN issue that was introduce by CAAM backlogging support[1].
This is fixed for SKCIPHER, HASH, RSA and AEAD algorithms.
[1] https://patchwork.kernel.org/cover/11378941/
Iuliana Prodan (4):
crypto: caam - fix use-after-free KASAN issue for SKCIPHER algorithms
crypto: caam - fix use-after-free KASAN issue for AEAD algorithms
crypto: caam - fix use-after-free KASAN issue for HASH algorithms
crypto: caam - fix use-after-free KASAN issue for RSA algorithms
drivers/crypto/caam/caamalg.c | 8 ++++----
drivers/crypto/caam/caamhash.c | 5 +++--
drivers/crypto/caam/caampkc.c | 6 ++++--
3 files changed, 11 insertions(+), 8 deletions(-)
--
2.1.0
Here's the KASAN report:
BUG: KASAN: use-after-free in aead_crypt_done+0x60/0xd8
Read of size 1 at addr ffff00002303f014 by task swapper/0/0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc1-00163-gd88dd5c-dirty #18
Hardware name: LS1046A RDB Board (DT)
Call trace:
dump_backtrace+0x0/0x260
show_stack+0x14/0x20
dump_stack+0xe8/0x144
print_address_description.isra.11+0x64/0x348
__kasan_report+0x11c/0x230
kasan_report+0xc/0x18
__asan_load1+0x5c/0x68
aead_crypt_done+0x60/0xd8
caam_jr_dequeue+0x390/0x608
...
Fixes: 1c2402266713 ("crypto: caam - add crypto_engine support for AEAD algorithms")
Signed-off-by: Iuliana Prodan <[email protected]>
---
drivers/crypto/caam/caamalg.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/crypto/caam/caamalg.c b/drivers/crypto/caam/caamalg.c
index 5538539..6d746ef 100644
--- a/drivers/crypto/caam/caamalg.c
+++ b/drivers/crypto/caam/caamalg.c
@@ -973,8 +973,6 @@ static void aead_crypt_done(struct device *jrdev, u32 *desc, u32 err,
aead_unmap(jrdev, edesc, req);
- kfree(edesc);
-
/*
* If no backlog flag, the completion of the request is done
* by CAAM, not crypto engine.
@@ -983,6 +981,8 @@ static void aead_crypt_done(struct device *jrdev, u32 *desc, u32 err,
aead_request_complete(req, ecode);
else
crypto_finalize_aead_request(jrp->engine, req, ecode);
+
+ kfree(edesc);
}
static void skcipher_crypt_done(struct device *jrdev, u32 *desc, u32 err,
--
2.1.0
Here's the KASAN report:
BUG: KASAN: use-after-free in ahash_done+0xdc/0x3b8
Read of size 1 at addr ffff000022e75510 by task swapper/0/0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc1-00164-gcb59d59-dirty #20
Hardware name: LS1046A RDB Board (DT)
Call trace:
dump_backtrace+0x0/0x260
show_stack+0x14/0x20
dump_stack+0xe8/0x144
print_address_description.isra.11+0x64/0x348
__kasan_report+0x11c/0x230
kasan_report+0xc/0x18
__asan_load1+0x5c/0x68
ahash_done+0xdc/0x3b8
caam_jr_dequeue+0x390/0x608
tasklet_action_common.isra.13+0x1ec/0x230
Fixes: 21b014f038d3 ("crypto: caam - add crypto_engine support for HASH algorithms")
Signed-off-by: Iuliana Prodan <[email protected]>
---
drivers/crypto/caam/caamhash.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/crypto/caam/caamhash.c b/drivers/crypto/caam/caamhash.c
index 943bc02..3c63fe0 100644
--- a/drivers/crypto/caam/caamhash.c
+++ b/drivers/crypto/caam/caamhash.c
@@ -593,7 +593,6 @@ static inline void ahash_done_cpy(struct device *jrdev, u32 *desc, u32 err,
ahash_unmap_ctx(jrdev, edesc, req, digestsize, dir);
memcpy(req->result, state->caam_ctx, digestsize);
- kfree(edesc);
print_hex_dump_debug("ctx@"__stringify(__LINE__)": ",
DUMP_PREFIX_ADDRESS, 16, 4, state->caam_ctx,
@@ -607,6 +606,8 @@ static inline void ahash_done_cpy(struct device *jrdev, u32 *desc, u32 err,
req->base.complete(&req->base, ecode);
else
crypto_finalize_hash_request(jrp->engine, req, ecode);
+
+ kfree(edesc);
}
static void ahash_done(struct device *jrdev, u32 *desc, u32 err,
@@ -640,7 +641,6 @@ static inline void ahash_done_switch(struct device *jrdev, u32 *desc, u32 err,
ecode = caam_jr_strstatus(jrdev, err);
ahash_unmap_ctx(jrdev, edesc, req, ctx->ctx_len, dir);
- kfree(edesc);
scatterwalk_map_and_copy(state->buf, req->src,
req->nbytes - state->next_buflen,
@@ -668,6 +668,7 @@ static inline void ahash_done_switch(struct device *jrdev, u32 *desc, u32 err,
else
crypto_finalize_hash_request(jrp->engine, req, ecode);
+ kfree(edesc);
}
static void ahash_done_bi(struct device *jrdev, u32 *desc, u32 err,
--
2.1.0
On 4/5/2020 2:50 PM, Iuliana Prodan wrote:
> Here's the KASAN report:
> BUG: KASAN: use-after-free in aead_crypt_done+0x60/0xd8
> Read of size 1 at addr ffff00002303f014 by task swapper/0/0
>
> CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.6.0-rc1-00163-gd88dd5c-dirty #18
This is no a public SHA1, you are probably running with patch 1/4
applied in the tree (and with a "dirty tree").
> Hardware name: LS1046A RDB Board (DT)
> Call trace:
> dump_backtrace+0x0/0x260
> show_stack+0x14/0x20
> dump_stack+0xe8/0x144
> print_address_description.isra.11+0x64/0x348
> __kasan_report+0x11c/0x230
> kasan_report+0xc/0x18
> __asan_load1+0x5c/0x68
> aead_crypt_done+0x60/0xd8
> caam_jr_dequeue+0x390/0x608
> ...
You should provide full KASan log - shawdow bits etc.
> @@ -973,8 +973,6 @@ static void aead_crypt_done(struct device *jrdev, u32 *desc, u32 err,
>
> aead_unmap(jrdev, edesc, req);
>
> - kfree(edesc);
> -
> /*
> * If no backlog flag, the completion of the request is done
> * by CAAM, not crypto engine.
> @@ -983,6 +981,8 @@ static void aead_crypt_done(struct device *jrdev, u32 *desc, u32 err,
> aead_request_complete(req, ecode);
> else
> crypto_finalize_aead_request(jrp->engine, req, ecode);
> +
> + kfree(edesc);
I think it's better freeing all resources before calling
the completion callback, to avoid unnecessary memory strains.
Horia