From: Kees Cook <keescook@xxxxxxxxxxxx> [ Upstream commit 5642c82b9463c3263c086efb002516244bd4c668 ] A potential string truncation was reported in bnx2x_fill_fw_str(), when a long bp->fw_ver and a long phy_fw_ver might coexist, but seems unlikely with real-world hardware. Use scnprintf() to indicate the intent that truncations are tolerated. While reading this code, I found a collection of various buffer size counting issues. None looked like they might lead to a buffer overflow with current code (the small buffers are 20 bytes and might only ever consume 10 bytes twice with a trailing %NUL). However, early truncation (due to a %NUL in the middle of the string) might be happening under likely rare conditions. Regardless fix the formatters and related functions: - Switch from a separate strscpy() to just adding an additional "%s" to the format string that immediately follows it in bnx2x_fill_fw_str(). - Use sizeof() universally instead of using unbound defines. - Fix bnx2x_7101_format_ver() and bnx2x_null_format_ver() to report the number of characters written, not including the trailing %NUL (as already done with the other firmware formatting functions). - Require space for at least 1 byte in bnx2x_get_ext_phy_fw_version() for the trailing %NUL. - Correct the needed buffer size in bnx2x_3_seq_format_ver(). Reported-by: kernel test robot <lkp@xxxxxxxxx> Closes: https://lore.kernel.org/oe-kbuild-all/202401260858.jZN6vD1k-lkp@xxxxxxxxx/ Cc: Ariel Elior <aelior@xxxxxxxxxxx> Cc: Sudarsana Kalluru <skalluru@xxxxxxxxxxx> Cc: Manish Chopra <manishc@xxxxxxxxxxx> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20240126041044.work.220-kees@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c | 9 +++++---- .../net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c | 2 +- drivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c | 14 +++++++------- 3 files changed, 13 insertions(+), 12 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c index e9c1e1bb55806..528441b28c4ef 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c @@ -147,10 +147,11 @@ void bnx2x_fill_fw_str(struct bnx2x *bp, char *buf, size_t buf_len) phy_fw_ver[0] = '\0'; bnx2x_get_ext_phy_fw_version(&bp->link_params, - phy_fw_ver, PHY_FW_VER_LEN); - strscpy(buf, bp->fw_ver, buf_len); - snprintf(buf + strlen(bp->fw_ver), 32 - strlen(bp->fw_ver), - "bc %d.%d.%d%s%s", + phy_fw_ver, sizeof(phy_fw_ver)); + /* This may become truncated. */ + scnprintf(buf, buf_len, + "%sbc %d.%d.%d%s%s", + bp->fw_ver, (bp->common.bc_ver & 0xff0000) >> 16, (bp->common.bc_ver & 0xff00) >> 8, (bp->common.bc_ver & 0xff), diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c index 81d232e6d05fe..0bc7690cdee16 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c @@ -1132,7 +1132,7 @@ static void bnx2x_get_drvinfo(struct net_device *dev, } memset(version, 0, sizeof(version)); - bnx2x_fill_fw_str(bp, version, ETHTOOL_FWVERS_LEN); + bnx2x_fill_fw_str(bp, version, sizeof(version)); strlcat(info->fw_version, version, sizeof(info->fw_version)); strscpy(info->bus_info, pci_name(bp->pdev), sizeof(info->bus_info)); diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c index 02808513ffe45..ea310057fe3af 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c @@ -6163,8 +6163,8 @@ static void bnx2x_link_int_ack(struct link_params *params, static int bnx2x_null_format_ver(u32 spirom_ver, u8 *str, u16 *len) { - str[0] = '\0'; - (*len)--; + if (*len) + str[0] = '\0'; return 0; } @@ -6173,7 +6173,7 @@ static int bnx2x_format_ver(u32 num, u8 *str, u16 *len) u16 ret; if (*len < 10) { - /* Need more than 10chars for this format */ + /* Need more than 10 chars for this format */ bnx2x_null_format_ver(num, str, len); return -EINVAL; } @@ -6188,8 +6188,8 @@ static int bnx2x_3_seq_format_ver(u32 num, u8 *str, u16 *len) { u16 ret; - if (*len < 10) { - /* Need more than 10chars for this format */ + if (*len < 9) { + /* Need more than 9 chars for this format */ bnx2x_null_format_ver(num, str, len); return -EINVAL; } @@ -6208,7 +6208,7 @@ int bnx2x_get_ext_phy_fw_version(struct link_params *params, u8 *version, int status = 0; u8 *ver_p = version; u16 remain_len = len; - if (version == NULL || params == NULL) + if (version == NULL || params == NULL || len == 0) return -EINVAL; bp = params->bp; @@ -11546,7 +11546,7 @@ static int bnx2x_7101_format_ver(u32 spirom_ver, u8 *str, u16 *len) str[2] = (spirom_ver & 0xFF0000) >> 16; str[3] = (spirom_ver & 0xFF000000) >> 24; str[4] = '\0'; - *len -= 5; + *len -= 4; return 0; } -- 2.43.0
