Instead of copying @buf into a new buffer and carefully managing its newline/null-terminating status, we can just use sysfs_match_string() as it uses sysfs_streq() internally which handles newline/null-term: | /** | * sysfs_streq - return true if strings are equal, modulo trailing newline | * @s1: one string | * @s2: another string | * | * This routine returns true iff two strings are equal, treating both | * NUL and newline-then-NUL as equivalent string terminations. It's | * geared for use with sysfs input strings, which generally terminate | * with newlines but are compared against values without newlines. | */ | bool sysfs_streq(const char *s1, const char *s2) | ... Then entirely drop the now unused fcoe_parse_mode, being careful to change if condition from checking for FIP_CONN_TYPE_UNKNOWN to < 0 as sysfs_match_string can return -EINVAL. Also check explicitly if ctlr->mode is equal to FIP_CONN_TYPE_UNKNOWN -- this is probably preferred to "<=" as the behavior is more obvious while maintaining functionality. To get the compiler not to complain, make fip_conn_type_names const char * const. Perhaps, this should also be done for fcf_state_names. This also removes an instance of strncpy() which helps [1]. Link: https://github.com/KSPP/linux/issues/90 [1] Cc: linux-hardening@xxxxxxxxxxxxxxx Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx> --- Changes in v2: - update if-cond to check for unknown type (thanks Kees) - Link to v1: https://lore.kernel.org/r/20231211-strncpy-drivers-scsi-fcoe-fcoe_sysfs-c-v1-1-73b942238396@xxxxxxxxxx --- Builds upon patch and feedback from [2]: However, this is different enough to warrant its own patch and not be a continuation. [2]: https://lore.kernel.org/all/9f38f4aa-c6b5-4786-a641-d02d8bd92f7f@xxxxxxx/ --- drivers/scsi/fcoe/fcoe_sysfs.c | 26 ++++---------------------- 1 file changed, 4 insertions(+), 22 deletions(-) diff --git a/drivers/scsi/fcoe/fcoe_sysfs.c b/drivers/scsi/fcoe/fcoe_sysfs.c index e17957f8085c..408a806bf4c2 100644 --- a/drivers/scsi/fcoe/fcoe_sysfs.c +++ b/drivers/scsi/fcoe/fcoe_sysfs.c @@ -10,6 +10,7 @@ #include <linux/kernel.h> #include <linux/etherdevice.h> #include <linux/ctype.h> +#include <linux/string.h> #include <scsi/fcoe_sysfs.h> #include <scsi/libfcoe.h> @@ -214,25 +215,13 @@ static const char *get_fcoe_##title##_name(enum table_type table_key) \ return table[table_key]; \ } -static char *fip_conn_type_names[] = { +static const char * const fip_conn_type_names[] = { [ FIP_CONN_TYPE_UNKNOWN ] = "Unknown", [ FIP_CONN_TYPE_FABRIC ] = "Fabric", [ FIP_CONN_TYPE_VN2VN ] = "VN2VN", }; fcoe_enum_name_search(ctlr_mode, fip_conn_type, fip_conn_type_names) -static enum fip_conn_type fcoe_parse_mode(const char *buf) -{ - int i; - - for (i = 0; i < ARRAY_SIZE(fip_conn_type_names); i++) { - if (strcasecmp(buf, fip_conn_type_names[i]) == 0) - return i; - } - - return FIP_CONN_TYPE_UNKNOWN; -} - static char *fcf_state_names[] = { [ FCOE_FCF_STATE_UNKNOWN ] = "Unknown", [ FCOE_FCF_STATE_DISCONNECTED ] = "Disconnected", @@ -274,17 +263,10 @@ static ssize_t store_ctlr_mode(struct device *dev, const char *buf, size_t count) { struct fcoe_ctlr_device *ctlr = dev_to_ctlr(dev); - char mode[FCOE_MAX_MODENAME_LEN + 1]; if (count > FCOE_MAX_MODENAME_LEN) return -EINVAL; - strncpy(mode, buf, count); - - if (mode[count - 1] == '\n') - mode[count - 1] = '\0'; - else - mode[count] = '\0'; switch (ctlr->enabled) { case FCOE_CTLR_ENABLED: @@ -297,8 +279,8 @@ static ssize_t store_ctlr_mode(struct device *dev, return -ENOTSUPP; } - ctlr->mode = fcoe_parse_mode(mode); - if (ctlr->mode == FIP_CONN_TYPE_UNKNOWN) { + ctlr->mode = sysfs_match_string(fip_conn_type_names, buf); + if (ctlr->mode < 0 || ctlr->mode == FIP_CONN_TYPE_UNKNOWN) { LIBFCOE_SYSFS_DBG(ctlr, "Unknown mode %s provided.\n", buf); return -EINVAL; --- base-commit: bee0e7762ad2c6025b9f5245c040fcc36ef2bde8 change-id: 20231024-strncpy-drivers-scsi-fcoe-fcoe_sysfs-c-0e1dffe82855 Best regards, -- Justin Stitt <justinstitt@xxxxxxxxxx>
