diff options
Diffstat (limited to 'drivers/md/dm-ioctl.c')
-rw-r--r-- | drivers/md/dm-ioctl.c | 108 |
1 files changed, 80 insertions, 28 deletions
diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 7d5c9c582ed2..f5ed729a8e0c 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -767,7 +767,14 @@ static int get_target_version(struct file *filp, struct dm_ioctl *param, size_t static int check_name(const char *name) { if (strchr(name, '/')) { - DMERR("invalid device name"); + DMERR("device name cannot contain '/'"); + return -EINVAL; + } + + if (strcmp(name, DM_CONTROL_NODE) == 0 || + strcmp(name, ".") == 0 || + strcmp(name, "..") == 0) { + DMERR("device name cannot be \"%s\", \".\", or \"..\"", DM_CONTROL_NODE); return -EINVAL; } @@ -861,7 +868,7 @@ static void __dev_status(struct mapped_device *md, struct dm_ioctl *param) table = dm_get_inactive_table(md, &srcu_idx); if (table) { - if (!(dm_table_get_mode(table) & FMODE_WRITE)) + if (!(dm_table_get_mode(table) & BLK_OPEN_WRITE)) param->flags |= DM_READONLY_FLAG; param->target_count = table->num_targets; } @@ -1189,7 +1196,7 @@ static int do_resume(struct dm_ioctl *param) if (old_size && new_size && old_size != new_size) need_resize_uevent = true; - if (dm_table_get_mode(new_map) & FMODE_WRITE) + if (dm_table_get_mode(new_map) & BLK_OPEN_WRITE) set_disk_ro(dm_disk(md), 0); else set_disk_ro(dm_disk(md), 1); @@ -1378,26 +1385,48 @@ static int dev_arm_poll(struct file *filp, struct dm_ioctl *param, size_t param_ return 0; } -static inline fmode_t get_mode(struct dm_ioctl *param) +static inline blk_mode_t get_mode(struct dm_ioctl *param) { - fmode_t mode = FMODE_READ | FMODE_WRITE; + blk_mode_t mode = BLK_OPEN_READ | BLK_OPEN_WRITE; if (param->flags & DM_READONLY_FLAG) - mode = FMODE_READ; + mode = BLK_OPEN_READ; return mode; } -static int next_target(struct dm_target_spec *last, uint32_t next, void *end, +static int next_target(struct dm_target_spec *last, uint32_t next, const char *end, struct dm_target_spec **spec, char **target_params) { - *spec = (struct dm_target_spec *) ((unsigned char *) last + next); - *target_params = (char *) (*spec + 1); + static_assert(__alignof__(struct dm_target_spec) <= 8, + "struct dm_target_spec must not require more than 8-byte alignment"); + + /* + * Number of bytes remaining, starting with last. This is always + * sizeof(struct dm_target_spec) or more, as otherwise *last was + * out of bounds already. + */ + size_t remaining = end - (char *)last; + + /* + * There must be room for both the next target spec and the + * NUL-terminator of the target itself. + */ + if (remaining - sizeof(struct dm_target_spec) <= next) { + DMERR("Target spec extends beyond end of parameters"); + return -EINVAL; + } - if (*spec < (last + 1)) + if (next % __alignof__(struct dm_target_spec)) { + DMERR("Next dm_target_spec (offset %u) is not %zu-byte aligned", + next, __alignof__(struct dm_target_spec)); return -EINVAL; + } + + *spec = (struct dm_target_spec *) ((unsigned char *) last + next); + *target_params = (char *) (*spec + 1); - return invalid_str(*target_params, end); + return 0; } static int populate_table(struct dm_table *table, @@ -1407,8 +1436,9 @@ static int populate_table(struct dm_table *table, unsigned int i = 0; struct dm_target_spec *spec = (struct dm_target_spec *) param; uint32_t next = param->data_start; - void *end = (void *) param + param_size; + const char *const end = (const char *) param + param_size; char *target_params; + size_t min_size = sizeof(struct dm_ioctl); if (!param->target_count) { DMERR("%s: no targets specified", __func__); @@ -1416,6 +1446,13 @@ static int populate_table(struct dm_table *table, } for (i = 0; i < param->target_count; i++) { + const char *nul_terminator; + + if (next < min_size) { + DMERR("%s: next target spec (offset %u) overlaps %s", + __func__, next, i ? "previous target" : "'struct dm_ioctl'"); + return -EINVAL; + } r = next_target(spec, next, end, &spec, &target_params); if (r) { @@ -1423,6 +1460,15 @@ static int populate_table(struct dm_table *table, return r; } + nul_terminator = memchr(target_params, 0, (size_t)(end - target_params)); + if (nul_terminator == NULL) { + DMERR("%s: target parameters not NUL-terminated", __func__); + return -EINVAL; + } + + /* Add 1 for NUL terminator */ + min_size = (size_t)(nul_terminator - (const char *)spec) + 1; + r = dm_table_add_target(table, spec->target_type, (sector_t) spec->sector_start, (sector_t) spec->length, @@ -1830,30 +1876,36 @@ static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags) * As well as checking the version compatibility this always * copies the kernel interface version out. */ -static int check_version(unsigned int cmd, struct dm_ioctl __user *user) +static int check_version(unsigned int cmd, struct dm_ioctl __user *user, + struct dm_ioctl *kernel_params) { - uint32_t version[3]; int r = 0; - if (copy_from_user(version, user->version, sizeof(version))) + /* Make certain version is first member of dm_ioctl struct */ + BUILD_BUG_ON(offsetof(struct dm_ioctl, version) != 0); + + if (copy_from_user(kernel_params->version, user->version, sizeof(kernel_params->version))) return -EFAULT; - if ((version[0] != DM_VERSION_MAJOR) || - (version[1] > DM_VERSION_MINOR)) { + if ((kernel_params->version[0] != DM_VERSION_MAJOR) || + (kernel_params->version[1] > DM_VERSION_MINOR)) { DMERR("ioctl interface mismatch: kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)", DM_VERSION_MAJOR, DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, - version[0], version[1], version[2], cmd); + kernel_params->version[0], + kernel_params->version[1], + kernel_params->version[2], + cmd); r = -EINVAL; } /* * Fill in the kernel version. */ - version[0] = DM_VERSION_MAJOR; - version[1] = DM_VERSION_MINOR; - version[2] = DM_VERSION_PATCHLEVEL; - if (copy_to_user(user->version, version, sizeof(version))) + kernel_params->version[0] = DM_VERSION_MAJOR; + kernel_params->version[1] = DM_VERSION_MINOR; + kernel_params->version[2] = DM_VERSION_PATCHLEVEL; + if (copy_to_user(user->version, kernel_params->version, sizeof(kernel_params->version))) return -EFAULT; return r; @@ -1877,9 +1929,11 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern struct dm_ioctl *dmi; int secure_data; const size_t minimum_data_size = offsetof(struct dm_ioctl, data); - unsigned int noio_flag; - if (copy_from_user(param_kernel, user, minimum_data_size)) + /* check_version() already copied version from userspace, avoid TOCTOU */ + if (copy_from_user((char *)param_kernel + sizeof(param_kernel->version), + (char __user *)user + sizeof(param_kernel->version), + minimum_data_size - sizeof(param_kernel->version))) return -EFAULT; if (param_kernel->data_size < minimum_data_size) { @@ -1904,9 +1958,7 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kern * Use kmalloc() rather than vmalloc() when we can. */ dmi = NULL; - noio_flag = memalloc_noio_save(); - dmi = kvmalloc(param_kernel->data_size, GFP_KERNEL | __GFP_HIGH); - memalloc_noio_restore(noio_flag); + dmi = kvmalloc(param_kernel->data_size, GFP_NOIO | __GFP_HIGH); if (!dmi) { if (secure_data && clear_user(user, param_kernel->data_size)) @@ -1991,7 +2043,7 @@ static int ctl_ioctl(struct file *file, uint command, struct dm_ioctl __user *us * Check the interface version passed in. This also * writes out the kernel's interface version. */ - r = check_version(cmd, user); + r = check_version(cmd, user, ¶m_kernel); if (r) return r; |