| Message ID | 20241218-crypto-qce-sha-fix-clang-cleanup-error-v1-1-7e6c6dcca345@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | crypto: qce - revert "use __free() for a buffer that's always freed" | expand |
On Wed, Dec 18, 2024 at 9:13 PM Nathan Chancellor <nathan@kernel.org> wrote: > > Commit ce8fd0500b74 ("crypto: qce - use __free() for a buffer that's > always freed") introduced a buggy use of __free(), which clang > rightfully points out: > > drivers/crypto/qce/sha.c:365:3: error: cannot jump from this goto statement to its label > 365 | goto err_free_ahash; > | ^ > drivers/crypto/qce/sha.c:373:6: note: jump bypasses initialization of variable with __attribute__((cleanup)) > 373 | u8 *buf __free(kfree) = kzalloc(keylen + QCE_MAX_ALIGN_SIZE, > | ^ > > Jumping over a variable declared with the cleanup attribute does not > prevent the cleanup function from running; instead, the cleanup function > is called with an uninitialized value. > > Moving the declaration back to the top function with __free() and a NULL > initialization would resolve the bug but that is really not much > different from the original code. Since the function is so simple and > there is no functional reason to use __free() here, just revert the > original change to resolve the issue. > > Fixes: ce8fd0500b74 ("crypto: qce - use __free() for a buffer that's always freed") > Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> > Closes: https://lore.kernel.org/CA+G9fYtpAwXa5mUQ5O7vDLK2xN4t-kJoxgUe1ZFRT=AGqmLSRA@mail.gmail.com/ > Signed-off-by: Nathan Chancellor <nathan@kernel.org> > --- Yeah, that was probably overkill but I thought it makes sense if I'm reworking the driver anyway. Feel free to kill it. Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
diff --git a/drivers/crypto/qce/sha.c b/drivers/crypto/qce/sha.c index c4ddc3b265eedecfd048662dc8935aa3e20fc646..71b748183cfa86fb850487374dcc24c4b0b8143f 100644 --- a/drivers/crypto/qce/sha.c +++ b/drivers/crypto/qce/sha.c @@ -3,7 +3,6 @@ * Copyright (c) 2010-2014, The Linux Foundation. All rights reserved. */ -#include <linux/cleanup.h> #include <linux/device.h> #include <linux/dma-mapping.h> #include <linux/interrupt.h> @@ -337,6 +336,7 @@ static int qce_ahash_hmac_setkey(struct crypto_ahash *tfm, const u8 *key, struct scatterlist sg; unsigned int blocksize; struct crypto_ahash *ahash_tfm; + u8 *buf; int ret; const char *alg_name; @@ -370,8 +370,7 @@ static int qce_ahash_hmac_setkey(struct crypto_ahash *tfm, const u8 *key, crypto_req_done, &wait); crypto_ahash_clear_flags(ahash_tfm, ~0); - u8 *buf __free(kfree) = kzalloc(keylen + QCE_MAX_ALIGN_SIZE, - GFP_KERNEL); + buf = kzalloc(keylen + QCE_MAX_ALIGN_SIZE, GFP_KERNEL); if (!buf) { ret = -ENOMEM; goto err_free_req; @@ -383,6 +382,7 @@ static int qce_ahash_hmac_setkey(struct crypto_ahash *tfm, const u8 *key, ret = crypto_wait_req(crypto_ahash_digest(req), &wait); + kfree(buf); err_free_req: ahash_request_free(req); err_free_ahash:
Commit ce8fd0500b74 ("crypto: qce - use __free() for a buffer that's always freed") introduced a buggy use of __free(), which clang rightfully points out: drivers/crypto/qce/sha.c:365:3: error: cannot jump from this goto statement to its label 365 | goto err_free_ahash; | ^ drivers/crypto/qce/sha.c:373:6: note: jump bypasses initialization of variable with __attribute__((cleanup)) 373 | u8 *buf __free(kfree) = kzalloc(keylen + QCE_MAX_ALIGN_SIZE, | ^ Jumping over a variable declared with the cleanup attribute does not prevent the cleanup function from running; instead, the cleanup function is called with an uninitialized value. Moving the declaration back to the top function with __free() and a NULL initialization would resolve the bug but that is really not much different from the original code. Since the function is so simple and there is no functional reason to use __free() here, just revert the original change to resolve the issue. Fixes: ce8fd0500b74 ("crypto: qce - use __free() for a buffer that's always freed") Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Closes: https://lore.kernel.org/CA+G9fYtpAwXa5mUQ5O7vDLK2xN4t-kJoxgUe1ZFRT=AGqmLSRA@mail.gmail.com/ Signed-off-by: Nathan Chancellor <nathan@kernel.org> --- drivers/crypto/qce/sha.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- base-commit: f916e44487f56df4827069ff3a2070c0746dc511 change-id: 20241218-crypto-qce-sha-fix-clang-cleanup-error-0e40766633d2 Best regards,