From 607bcc4213d998d051541d8f10b5bbb7d546c0be Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Sat, 29 Jul 2023 20:59:25 +0200 Subject: [PATCH] media: i2c: ccs: Check rules is non-NULL Fix the following smatch warning: drivers/media/i2c/ccs/ccs-data.c:524 ccs_data_parse_rules() warn: address of NULL pointer 'rules' The CCS static data rule parser does not check an if rule has been obtained before checking for other rule types (which depend on the if rule). In practice this means parsing invalid CCS static data could lead to dereferencing a NULL pointer. Reported-by: Hans Verkuil Fixes: a6b396f410b1 ("media: ccs: Add CCS static data parser library") Cc: stable@vger.kernel.org # for 5.11 and up Signed-off-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- drivers/media/i2c/ccs/ccs-data.c | 101 ++++++++++++++++++++++----------------- 1 file changed, 56 insertions(+), 45 deletions(-) diff --git a/drivers/media/i2c/ccs/ccs-data.c b/drivers/media/i2c/ccs/ccs-data.c index 45f2b2f..08400ed 100644 --- a/drivers/media/i2c/ccs/ccs-data.c +++ b/drivers/media/i2c/ccs/ccs-data.c @@ -464,8 +464,7 @@ static int ccs_data_parse_rules(struct bin_container *bin, rule_payload = __rule_type + 1; rule_plen2 = rule_plen - sizeof(*__rule_type); - switch (*__rule_type) { - case CCS_DATA_BLOCK_RULE_ID_IF: { + if (*__rule_type == CCS_DATA_BLOCK_RULE_ID_IF) { const struct __ccs_data_block_rule_if *__if_rules = rule_payload; const size_t __num_if_rules = @@ -514,49 +513,61 @@ static int ccs_data_parse_rules(struct bin_container *bin, rules->if_rules = if_rule; rules->num_if_rules = __num_if_rules; } - break; - } - case CCS_DATA_BLOCK_RULE_ID_READ_ONLY_REGS: - rval = ccs_data_parse_reg_rules(bin, &rules->read_only_regs, - &rules->num_read_only_regs, - rule_payload, - rule_payload + rule_plen2, - dev); - if (rval) - return rval; - break; - case CCS_DATA_BLOCK_RULE_ID_FFD: - rval = ccs_data_parse_ffd(bin, &rules->frame_format, - rule_payload, - rule_payload + rule_plen2, - dev); - if (rval) - return rval; - break; - case CCS_DATA_BLOCK_RULE_ID_MSR: - rval = ccs_data_parse_reg_rules(bin, - &rules->manufacturer_regs, - &rules->num_manufacturer_regs, - rule_payload, - rule_payload + rule_plen2, - dev); - if (rval) - return rval; - break; - case CCS_DATA_BLOCK_RULE_ID_PDAF_READOUT: - rval = ccs_data_parse_pdaf_readout(bin, - &rules->pdaf_readout, - rule_payload, - rule_payload + rule_plen2, - dev); - if (rval) - return rval; - break; - default: - dev_dbg(dev, - "Don't know how to handle rule type %u!\n", - *__rule_type); - return -EINVAL; + } else { + /* Check there was an if rule before any other rules */ + if (bin->base && !rules) + return -EINVAL; + + switch (*__rule_type) { + case CCS_DATA_BLOCK_RULE_ID_READ_ONLY_REGS: + rval = ccs_data_parse_reg_rules(bin, + rules ? + &rules->read_only_regs : NULL, + rules ? + &rules->num_read_only_regs : NULL, + rule_payload, + rule_payload + rule_plen2, + dev); + if (rval) + return rval; + break; + case CCS_DATA_BLOCK_RULE_ID_FFD: + rval = ccs_data_parse_ffd(bin, rules ? + &rules->frame_format : NULL, + rule_payload, + rule_payload + rule_plen2, + dev); + if (rval) + return rval; + break; + case CCS_DATA_BLOCK_RULE_ID_MSR: + rval = ccs_data_parse_reg_rules(bin, + rules ? + &rules->manufacturer_regs : NULL, + rules ? + &rules->num_manufacturer_regs : NULL, + rule_payload, + rule_payload + rule_plen2, + dev); + if (rval) + return rval; + break; + case CCS_DATA_BLOCK_RULE_ID_PDAF_READOUT: + rval = ccs_data_parse_pdaf_readout(bin, + rules ? + &rules->pdaf_readout : NULL, + rule_payload, + rule_payload + rule_plen2, + dev); + if (rval) + return rval; + break; + default: + dev_dbg(dev, + "Don't know how to handle rule type %u!\n", + *__rule_type); + return -EINVAL; + } } __next_rule = __next_rule + rule_hlen + rule_plen; } -- 2.7.4