From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: From: Kees Cook To: Jens Axboe Cc: Kees Cook , "Martin K. Petersen" , James Bottomley , Tejun Heo , Borislav Petkov , "David S. Miller" , "Manoj N. Kumar" , "Matthew R. Ochs" , Uma Krishnan , linux-block@vger.kernel.org, linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 6/6] scsi: Check sense buffer size at build time Date: Tue, 22 May 2018 11:15:12 -0700 Message-Id: <20180522181512.39316-7-keescook@chromium.org> In-Reply-To: <20180522181512.39316-1-keescook@chromium.org> References: <20180522181512.39316-1-keescook@chromium.org> List-ID: To avoid introducing problems like those fixed in commit f7068114d45e ("sr: pass down correctly sized SCSI sense buffer"), this creates a macro wrapper for scsi_execute() that verifies the size of the sense buffer similar to what was done for command string sizes in commit 3756f6401c30 ("exec: avoid gcc-8 warning for get_task_comm"). Another solution could be to add another argument to scsi_execute(), but this function already takes a lot of arguments and Jens was not fond of that approach. As there was only a pair of dynamically allocated sense buffers, this also moves those 96 bytes onto the stack to avoid triggering the sizeof() check. Signed-off-by: Kees Cook --- drivers/scsi/scsi_lib.c | 6 +++--- include/scsi/scsi_device.h | 12 +++++++++++- 2 files changed, 14 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index e9b4f279d29c..718c2bec4516 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -238,7 +238,7 @@ void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) /** - * scsi_execute - insert request and wait for the result + * __scsi_execute - insert request and wait for the result * @sdev: scsi device * @cmd: scsi command * @data_direction: data direction @@ -255,7 +255,7 @@ void scsi_queue_insert(struct scsi_cmnd *cmd, int reason) * Returns the scsi_cmnd result field if a command was executed, or a negative * Linux error code if we didn't get that far. */ -int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, +int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, int data_direction, void *buffer, unsigned bufflen, unsigned char *sense, struct scsi_sense_hdr *sshdr, int timeout, int retries, u64 flags, req_flags_t rq_flags, @@ -309,7 +309,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, return ret; } -EXPORT_SYMBOL(scsi_execute); +EXPORT_SYMBOL(__scsi_execute); /* * Function: scsi_init_cmd_errh() diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 7ae177c8e399..1bb87b6c0ad2 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.h @@ -426,11 +426,21 @@ extern const char *scsi_device_state_name(enum scsi_device_state); extern int scsi_is_sdev_device(const struct device *); extern int scsi_is_target_device(const struct device *); extern void scsi_sanitize_inquiry_string(unsigned char *s, int len); -extern int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, +extern int __scsi_execute(struct scsi_device *sdev, const unsigned char *cmd, int data_direction, void *buffer, unsigned bufflen, unsigned char *sense, struct scsi_sense_hdr *sshdr, int timeout, int retries, u64 flags, req_flags_t rq_flags, int *resid); +/* Make sure any sense buffer is the correct size. */ +#define scsi_execute(sdev, cmd, data_direction, buffer, bufflen, sense, \ + sshdr, timeout, retries, flags, rq_flags, resid) \ +({ \ + BUILD_BUG_ON((sense) != NULL && \ + sizeof(sense) != SCSI_SENSE_BUFFERSIZE); \ + __scsi_execute(sdev, cmd, data_direction, buffer, bufflen, \ + sense, sshdr, timeout, retries, flags, rq_flags, \ + resid); \ +}) static inline int scsi_execute_req(struct scsi_device *sdev, const unsigned char *cmd, int data_direction, void *buffer, unsigned bufflen, struct scsi_sense_hdr *sshdr, int timeout, -- 2.17.0