diff options
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/md/dm-verity-loadpin.c | 8 | ||||
-rw-r--r-- | drivers/md/dm-verity-target.c | 16 | ||||
-rw-r--r-- | drivers/md/dm-verity.h | 1 | ||||
-rw-r--r-- | drivers/misc/lkdtm/fortify.c | 96 |
4 files changed, 108 insertions, 13 deletions
diff --git a/drivers/md/dm-verity-loadpin.c b/drivers/md/dm-verity-loadpin.c index 387ec43aef72..4f78cc55c251 100644 --- a/drivers/md/dm-verity-loadpin.c +++ b/drivers/md/dm-verity-loadpin.c @@ -14,6 +14,7 @@ LIST_HEAD(dm_verity_loadpin_trusted_root_digests); static bool is_trusted_verity_target(struct dm_target *ti) { + int verity_mode; u8 *root_digest; unsigned int digest_size; struct dm_verity_loadpin_trusted_root_digest *trd; @@ -22,6 +23,13 @@ static bool is_trusted_verity_target(struct dm_target *ti) if (!dm_is_verity_target(ti)) return false; + verity_mode = dm_verity_get_mode(ti); + + if ((verity_mode != DM_VERITY_MODE_EIO) && + (verity_mode != DM_VERITY_MODE_RESTART) && + (verity_mode != DM_VERITY_MODE_PANIC)) + return false; + if (dm_verity_get_root_digest(ti, &root_digest, &digest_size)) return false; diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c index 94b6cb599db4..8a00cc42e498 100644 --- a/drivers/md/dm-verity-target.c +++ b/drivers/md/dm-verity-target.c @@ -1447,6 +1447,22 @@ bool dm_is_verity_target(struct dm_target *ti) } /* + * Get the verity mode (error behavior) of a verity target. + * + * Returns the verity mode of the target, or -EINVAL if 'ti' is not a verity + * target. + */ +int dm_verity_get_mode(struct dm_target *ti) +{ + struct dm_verity *v = ti->private; + + if (!dm_is_verity_target(ti)) + return -EINVAL; + + return v->mode; +} + +/* * Get the root digest of a verity target. * * Returns a copy of the root digest, the caller is responsible for diff --git a/drivers/md/dm-verity.h b/drivers/md/dm-verity.h index 45455de1b4bc..98f306ec6a33 100644 --- a/drivers/md/dm-verity.h +++ b/drivers/md/dm-verity.h @@ -134,6 +134,7 @@ extern int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io, sector_t block, u8 *digest, bool *is_zero); extern bool dm_is_verity_target(struct dm_target *ti); +extern int dm_verity_get_mode(struct dm_target *ti); extern int dm_verity_get_root_digest(struct dm_target *ti, u8 **root_digest, unsigned int *digest_size); diff --git a/drivers/misc/lkdtm/fortify.c b/drivers/misc/lkdtm/fortify.c index 080293fa3c52..015927665678 100644 --- a/drivers/misc/lkdtm/fortify.c +++ b/drivers/misc/lkdtm/fortify.c @@ -10,28 +10,31 @@ static volatile int fortify_scratch_space; -static void lkdtm_FORTIFIED_OBJECT(void) +static void lkdtm_FORTIFY_STR_OBJECT(void) { struct target { char a[10]; - } target[2] = {}; + int foo; + } target[3] = {}; /* * Using volatile prevents the compiler from determining the value of * 'size' at compile time. Without that, we would get a compile error * rather than a runtime error. */ - volatile int size = 11; + volatile int size = 20; + + pr_info("trying to strcmp() past the end of a struct\n"); - pr_info("trying to read past the end of a struct\n"); + strncpy(target[0].a, target[1].a, size); /* Store result to global to prevent the code from being eliminated */ - fortify_scratch_space = memcmp(&target[0], &target[1], size); + fortify_scratch_space = target[0].a[3]; - pr_err("FAIL: fortify did not block an object overread!\n"); + pr_err("FAIL: fortify did not block a strncpy() object write overflow!\n"); pr_expected_config(CONFIG_FORTIFY_SOURCE); } -static void lkdtm_FORTIFIED_SUBOBJECT(void) +static void lkdtm_FORTIFY_STR_MEMBER(void) { struct target { char a[10]; @@ -44,7 +47,7 @@ static void lkdtm_FORTIFIED_SUBOBJECT(void) strscpy(src, "over ten bytes", size); size = strlen(src) + 1; - pr_info("trying to strncpy past the end of a member of a struct\n"); + pr_info("trying to strncpy() past the end of a struct member...\n"); /* * strncpy(target.a, src, 20); will hit a compile error because the @@ -56,7 +59,72 @@ static void lkdtm_FORTIFIED_SUBOBJECT(void) /* Store result to global to prevent the code from being eliminated */ fortify_scratch_space = target.a[3]; - pr_err("FAIL: fortify did not block an sub-object overrun!\n"); + pr_err("FAIL: fortify did not block a strncpy() struct member write overflow!\n"); + pr_expected_config(CONFIG_FORTIFY_SOURCE); + + kfree(src); +} + +static void lkdtm_FORTIFY_MEM_OBJECT(void) +{ + int before[10]; + struct target { + char a[10]; + int foo; + } target = {}; + int after[10]; + /* + * Using volatile prevents the compiler from determining the value of + * 'size' at compile time. Without that, we would get a compile error + * rather than a runtime error. + */ + volatile int size = 20; + + memset(before, 0, sizeof(before)); + memset(after, 0, sizeof(after)); + fortify_scratch_space = before[5]; + fortify_scratch_space = after[5]; + + pr_info("trying to memcpy() past the end of a struct\n"); + + pr_info("0: %zu\n", __builtin_object_size(&target, 0)); + pr_info("1: %zu\n", __builtin_object_size(&target, 1)); + pr_info("s: %d\n", size); + memcpy(&target, &before, size); + + /* Store result to global to prevent the code from being eliminated */ + fortify_scratch_space = target.a[3]; + + pr_err("FAIL: fortify did not block a memcpy() object write overflow!\n"); + pr_expected_config(CONFIG_FORTIFY_SOURCE); +} + +static void lkdtm_FORTIFY_MEM_MEMBER(void) +{ + struct target { + char a[10]; + char b[10]; + } target; + volatile int size = 20; + char *src; + + src = kmalloc(size, GFP_KERNEL); + strscpy(src, "over ten bytes", size); + size = strlen(src) + 1; + + pr_info("trying to memcpy() past the end of a struct member...\n"); + + /* + * strncpy(target.a, src, 20); will hit a compile error because the + * compiler knows at build time that target.a < 20 bytes. Use a + * volatile to force a runtime error. + */ + memcpy(target.a, src, size); + + /* Store result to global to prevent the code from being eliminated */ + fortify_scratch_space = target.a[3]; + + pr_err("FAIL: fortify did not block a memcpy() struct member write overflow!\n"); pr_expected_config(CONFIG_FORTIFY_SOURCE); kfree(src); @@ -67,7 +135,7 @@ static void lkdtm_FORTIFIED_SUBOBJECT(void) * strscpy and generate a panic because there is a write overflow (i.e. src * length is greater than dst length). */ -static void lkdtm_FORTIFIED_STRSCPY(void) +static void lkdtm_FORTIFY_STRSCPY(void) { char *src; char dst[5]; @@ -136,9 +204,11 @@ static void lkdtm_FORTIFIED_STRSCPY(void) } static struct crashtype crashtypes[] = { - CRASHTYPE(FORTIFIED_OBJECT), - CRASHTYPE(FORTIFIED_SUBOBJECT), - CRASHTYPE(FORTIFIED_STRSCPY), + CRASHTYPE(FORTIFY_STR_OBJECT), + CRASHTYPE(FORTIFY_STR_MEMBER), + CRASHTYPE(FORTIFY_MEM_OBJECT), + CRASHTYPE(FORTIFY_MEM_MEMBER), + CRASHTYPE(FORTIFY_STRSCPY), }; struct crashtype_category fortify_crashtypes = { |