From: Mostafa Saleh smostafa@google.com
Sashiko (locally) reports multiple out-of-bound issues in ffa_setup_and_transmit: 1) Writing ep_mem_access->reserved can write out of bounds for FFA versions < 1.2 as ffa_emad_size_get() returns 16 bytes in that case while reserved has an offset of 24. Instead of zeroing fields, memset the struct to zero first based on the FFA version.
2) Make sure there is enough size to write constituents.
While at it, convert the only sizeof() in the driver that uses a type instead of variable.
Reviewed-by: Sudeep Holla sudeep.holla@kernel.org Fixes: 111a833dc5cb ("firmware: arm_ffa: Set reserved/MBZ fields to zero in the memory descriptors") Signed-off-by: Mostafa Saleh smostafa@google.com Signed-off-by: Sebastian Ene sebastianene@google.com --- drivers/firmware/arm_ffa/driver.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/firmware/arm_ffa/driver.c b/drivers/firmware/arm_ffa/driver.c index 0f468362c288..01301213896a 100644 --- a/drivers/firmware/arm_ffa/driver.c +++ b/drivers/firmware/arm_ffa/driver.c @@ -725,11 +725,10 @@ ffa_setup_and_transmit(u32 func_id, void *buffer, u32 max_fragsize, for (idx = 0; idx < args->nattrs; idx++) { ep_mem_access = buffer + ffa_mem_desc_offset(buffer, idx, drv_info->version); + memset(ep_mem_access, 0, ffa_emad_size_get(drv_info->version)); ep_mem_access->receiver = args->attrs[idx].receiver; ep_mem_access->attrs = args->attrs[idx].attrs; ep_mem_access->composite_off = composite_offset; - ep_mem_access->flag = 0; - ep_mem_access->reserved = 0; ffa_emad_impdef_value_init(drv_info->version, ep_mem_access->impdef_val, args->attrs[idx].impdef_val); @@ -769,7 +768,7 @@ ffa_setup_and_transmit(u32 func_id, void *buffer, u32 max_fragsize, constituents = buffer; }
- if ((void *)constituents - buffer > max_fragsize) { + if ((void *)constituents + sizeof(*constituents) - buffer > max_fragsize) { pr_err("Memory Region Fragment > Tx Buffer size\n"); return -EFAULT; } @@ -778,7 +777,7 @@ ffa_setup_and_transmit(u32 func_id, void *buffer, u32 max_fragsize, constituents->pg_cnt = args->sg->length / FFA_PAGE_SIZE; constituents->reserved = 0; constituents++; - frag_len += sizeof(struct ffa_mem_region_addr_range); + frag_len += sizeof(*constituents); } while ((args->sg = sg_next(args->sg)));
return ffa_transmit_fragment(func_id, addr, buf_sz, frag_len,