From: Gokul krishna Krishnakumar quic_gokukris@quicinc.com
[ Upstream commit 210d12c8197a551caa2979be421aa42381156aec ]
It may be that the offset of the first program header lies inside the mdt's filesize, in this case the loader would incorrectly assume that the bins were not split and in this scenario the firmware authentication fails. This change updates the logic used by the mdt loader to understand whether the firmware images are split or not. It figures this out by checking if each programs header's segment lies within the file or not.
Co-developed-by: Melody Olvera quic_molvera@quicinc.com Signed-off-by: Melody Olvera quic_molvera@quicinc.com Signed-off-by: Gokul krishna Krishnakumar quic_gokukris@quicinc.com Signed-off-by: Bjorn Andersson andersson@kernel.org Link: https://lore.kernel.org/r/20230509001821.24010-1-quic_gokukris@quicinc.com Stable-dep-of: 9f9967fed9d0 ("soc: qcom: mdt_loader: Ensure we don't read past the ELF header") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/soc/qcom/mdt_loader.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-)
diff --git a/drivers/soc/qcom/mdt_loader.c b/drivers/soc/qcom/mdt_loader.c index 10235b36d131..c075d38f38fe 100644 --- a/drivers/soc/qcom/mdt_loader.c +++ b/drivers/soc/qcom/mdt_loader.c @@ -264,6 +264,26 @@ int qcom_mdt_pas_init(struct device *dev, const struct firmware *fw, } EXPORT_SYMBOL_GPL(qcom_mdt_pas_init);
+static bool qcom_mdt_bins_are_split(const struct firmware *fw, const char *fw_name) +{ + const struct elf32_phdr *phdrs; + const struct elf32_hdr *ehdr; + uint64_t seg_start, seg_end; + int i; + + ehdr = (struct elf32_hdr *)fw->data; + phdrs = (struct elf32_phdr *)(ehdr + 1); + + for (i = 0; i < ehdr->e_phnum; i++) { + seg_start = phdrs[i].p_offset; + seg_end = phdrs[i].p_offset + phdrs[i].p_filesz; + if (seg_start > fw->size || seg_end > fw->size) + return true; + } + + return false; +} + static int __qcom_mdt_load(struct device *dev, const struct firmware *fw, const char *fw_name, int pas_id, void *mem_region, phys_addr_t mem_phys, size_t mem_size, @@ -276,6 +296,7 @@ static int __qcom_mdt_load(struct device *dev, const struct firmware *fw, phys_addr_t min_addr = PHYS_ADDR_MAX; ssize_t offset; bool relocate = false; + bool is_split; void *ptr; int ret = 0; int i; @@ -283,6 +304,7 @@ static int __qcom_mdt_load(struct device *dev, const struct firmware *fw, if (!fw || !mem_region || !mem_phys || !mem_size) return -EINVAL;
+ is_split = qcom_mdt_bins_are_split(fw, fw_name); ehdr = (struct elf32_hdr *)fw->data; phdrs = (struct elf32_phdr *)(ehdr + 1);
@@ -336,8 +358,7 @@ static int __qcom_mdt_load(struct device *dev, const struct firmware *fw,
ptr = mem_region + offset;
- if (phdr->p_filesz && phdr->p_offset < fw->size && - phdr->p_offset + phdr->p_filesz <= fw->size) { + if (phdr->p_filesz && !is_split) { /* Firmware is large enough to be non-split */ if (phdr->p_offset + phdr->p_filesz > fw->size) { dev_err(dev, "file %s segment %d would be truncated\n",