Re: [PATCH] nouveau/gsp: Avoid addressing beyond end of rpc->entries
On 3/30/24 15:12, Kees Cook wrote: Using the end of rpc->entries[] for addressing runs into both compile-time and run-time detection of accessing beyond the end of the array. Use the base pointer instead, since was allocated with the additional bytes for storing the strings. Avoids the following warning in future GCC releases with support for __counted_by: In function 'fortify_memcpy_chk', inlined from 'r535_gsp_rpc_set_registry' at ../drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c:1123:3: ../include/linux/fortify-string.h:553:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] 553 | __write_overflow_field(p_size_field, size); | ^~ for this code: strings = (char *)&rpc->entries[NV_GSP_REG_NUM_ENTRIES]; ... memcpy(strings, r535_registry_entries[i].name, name_len); Signed-off-by: Kees Cook Applied to drm-misc-fixes, thanks! --- Cc: Karol Herbst Cc: Lyude Paul Cc: Danilo Krummrich Cc: David Airlie Cc: Daniel Vetter Cc: Dave Airlie Cc: Ben Skeggs Cc: Timur Tabi Cc: dri-devel@lists.freedesktop.org Cc: nouv...@lists.freedesktop.org --- drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c index 9994cbd6f1c4..9858c1438aa7 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c @@ -1112,7 +1112,7 @@ r535_gsp_rpc_set_registry(struct nvkm_gsp *gsp) rpc->numEntries = NV_GSP_REG_NUM_ENTRIES; str_offset = offsetof(typeof(*rpc), entries[NV_GSP_REG_NUM_ENTRIES]); - strings = (char *)&rpc->entries[NV_GSP_REG_NUM_ENTRIES]; + strings = (char *)rpc + str_offset; for (i = 0; i < NV_GSP_REG_NUM_ENTRIES; i++) { int name_len = strlen(r535_registry_entries[i].name) + 1;
[PATCH] nouveau/gsp: Avoid addressing beyond end of rpc->entries
Using the end of rpc->entries[] for addressing runs into both compile-time and run-time detection of accessing beyond the end of the array. Use the base pointer instead, since was allocated with the additional bytes for storing the strings. Avoids the following warning in future GCC releases with support for __counted_by: In function 'fortify_memcpy_chk', inlined from 'r535_gsp_rpc_set_registry' at ../drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c:1123:3: ../include/linux/fortify-string.h:553:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] 553 | __write_overflow_field(p_size_field, size); | ^~ for this code: strings = (char *)&rpc->entries[NV_GSP_REG_NUM_ENTRIES]; ... memcpy(strings, r535_registry_entries[i].name, name_len); Signed-off-by: Kees Cook --- Cc: Karol Herbst Cc: Lyude Paul Cc: Danilo Krummrich Cc: David Airlie Cc: Daniel Vetter Cc: Dave Airlie Cc: Ben Skeggs Cc: Timur Tabi Cc: dri-devel@lists.freedesktop.org Cc: nouv...@lists.freedesktop.org --- drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c index 9994cbd6f1c4..9858c1438aa7 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c @@ -1112,7 +1112,7 @@ r535_gsp_rpc_set_registry(struct nvkm_gsp *gsp) rpc->numEntries = NV_GSP_REG_NUM_ENTRIES; str_offset = offsetof(typeof(*rpc), entries[NV_GSP_REG_NUM_ENTRIES]); - strings = (char *)&rpc->entries[NV_GSP_REG_NUM_ENTRIES]; + strings = (char *)rpc + str_offset; for (i = 0; i < NV_GSP_REG_NUM_ENTRIES; i++) { int name_len = strlen(r535_registry_entries[i].name) + 1; -- 2.34.1