kernel/linux.git/drivers/base/firmware_loader/main.c, branch v5.10.78

firmware: fix theoretical UAF race with firmware cache and resume

2021-09-15T07:50:33+00:00

[ Upstream commit 3ecc8cb7c092b2f50e21d2aaaae35b8221ee7214 ] This race was discovered when I carefully analyzed the code to locate another firmware-related UAF issue. It can be triggered only when the firmware load operation is executed during suspend. This possibility is almost impossible because there are few firmware load and suspend actions in the actual environment. CPU0 CPU1 __device_uncache_fw_images(): assign_fw(): fw_cache_piggyback_on_request() <----- P0 spin_lock(&fwc->name_lock); ... list_del(&fce->list); spin_unlock(&fwc->name_lock); uncache_firmware(fce->name); <----- P1 kref_get(&fw_priv->ref); If CPU1 is interrupted at position P0, the new 'fce' has been added to the list fwc->fw_names by the fw_cache_piggyback_on_request(). In this case, CPU0 executes __device_uncache_fw_images() and will be able to see it when it traverses list fwc->fw_names. Before CPU1 executes kref_get() at P1, if CPU0 further executes uncache_firmware(), the count of fw_priv->ref may decrease to 0, causing fw_priv to be released in advance. Move kref_get() to the lock protection range of fwc->name_lock to fix it. Fixes: ac39b3ea73aa ("firmware loader: let caching firmware piggyback on loading firmware") Acked-by: Luis Chamberlain Signed-off-by: Zhen Lei Link: https://lore.kernel.org/r/20210719064531.3733-2-thunder.leizhen@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

firmware_loader: fix use-after-free in firmware_fallback_sysfs

2021-08-12T11:22:09+00:00

commit 75d95e2e39b27f733f21e6668af1c9893a97de5e upstream. This use-after-free happens when a fw_priv object has been freed but hasn't been removed from the pending list (pending_fw_head). The next time fw_load_sysfs_fallback tries to insert into the list, it ends up accessing the pending_list member of the previously freed fw_priv. The root cause here is that all code paths that abort the fw load don't delete it from the pending list. For example: _request_firmware() -> fw_abort_batch_reqs() -> fw_state_aborted() To fix this, delete the fw_priv from the list in __fw_set_state() if the new state is DONE or ABORTED. This way, all aborts will remove the fw_priv from the list. Accordingly, remove calls to list_del_init that were being made before calling fw_state_(aborted|done). Also, in fw_load_sysfs_fallback, don't add the fw_priv to the pending list if it is already aborted. Instead, just jump out and return early. Fixes: bcfbd3523f3c ("firmware: fix a double abort case with fw_load_sysfs_fallback") Cc: stable Reported-by: syzbot+de271708674e2093097b@syzkaller.appspotmail.com Tested-by: syzbot+de271708674e2093097b@syzkaller.appspotmail.com Reviewed-by: Shuah Khan Acked-by: Luis Chamberlain Signed-off-by: Anirudh Rayabharam Link: https://lore.kernel.org/r/20210728085107.4141-3-mail@anirudhrb.com Signed-off-by: Greg Kroah-Hartman

firmware: Add request_partial_firmware_into_buf()

2020-10-05T11:37:04+00:00

Add request_partial_firmware_into_buf() to allow for portions of a firmware file to be read into a buffer. This is needed when large firmware must be loaded in portions from a file on memory constrained systems. Signed-off-by: Scott Branden Co-developed-by: Kees Cook Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20201002173828.2099543-16-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

firmware: Store opt_flags in fw_priv

2020-10-05T11:37:04+00:00

Instead of passing opt_flags around so much, store it in the private structure so it can be examined by internals without needing to add more arguments to functions. Co-developed-by: Scott Branden Signed-off-by: Scott Branden Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20201002173828.2099543-15-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

fs/kernel_file_read: Add "offset" arg for partial reads

2020-10-05T11:37:04+00:00

To perform partial reads, callers of kernel_read_file*() must have a non-NULL file_size argument and a preallocated buffer. The new "offset" argument can then be used to seek to specific locations in the file to fill the buffer to, at most, "buf_size" per call. Where possible, the LSM hooks can report whether a full file has been read or not so that the contents can be reasoned about. Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20201002173828.2099543-14-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

fs/kernel_read_file: Add file_size output argument

2020-10-05T11:37:03+00:00

In preparation for adding partial read support, add an optional output argument to kernel_read_file*() that reports the file size so callers can reason more easily about their reading progress. Signed-off-by: Kees Cook Reviewed-by: Mimi Zohar Reviewed-by: Luis Chamberlain Reviewed-by: James Morris Acked-by: Scott Branden Link: https://lore.kernel.org/r/20201002173828.2099543-8-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

fs/kernel_read_file: Remove redundant size argument

2020-10-05T11:34:18+00:00

In preparation for refactoring kernel_read_file*(), remove the redundant "size" argument which is not needed: it can be included in the return code, with callers adjusted. (VFS reads already cannot be larger than INT_MAX.) Signed-off-by: Kees Cook Reviewed-by: Mimi Zohar Reviewed-by: Luis Chamberlain Reviewed-by: James Morris Acked-by: Scott Branden Link: https://lore.kernel.org/r/20201002173828.2099543-6-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

fs/kernel_read_file: Split into separate include file

2020-10-05T11:34:18+00:00

Move kernel_read_file* out of linux/fs.h to its own linux/kernel_read_file.h include file. That header gets pulled in just about everywhere and doesn't really need functions not related to the general fs interface. Suggested-by: Christoph Hellwig Signed-off-by: Scott Branden Signed-off-by: Kees Cook Reviewed-by: Christoph Hellwig Reviewed-by: Mimi Zohar Reviewed-by: Luis Chamberlain Acked-by: Greg Kroah-Hartman Acked-by: James Morris Link: https://lore.kernel.org/r/20200706232309.12010-2-scott.branden@broadcom.com Link: https://lore.kernel.org/r/20201002173828.2099543-4-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

fs/kernel_read_file: Remove FIRMWARE_PREALLOC_BUFFER enum

2020-10-05T11:34:18+00:00

FIRMWARE_PREALLOC_BUFFER is a "how", not a "what", and confuses the LSMs that are interested in filtering between types of things. The "how" should be an internal detail made uninteresting to the LSMs. Fixes: a098ecd2fa7d ("firmware: support loading into a pre-allocated buffer") Fixes: fd90bc559bfb ("ima: based on policy verify firmware signatures (pre-allocated buffer)") Fixes: 4f0496d8ffa3 ("ima: based on policy warn about loading firmware (pre-allocated buffer)") Signed-off-by: Kees Cook Reviewed-by: Mimi Zohar Reviewed-by: Luis Chamberlain Acked-by: Scott Branden Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201002173828.2099543-2-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

firmware_loader: fix memory leak for paged buffer

2020-08-28T09:32:07+00:00

vfree() is being called on paged buffer allocated using alloc_page() and mapped using vmap(). Freeing of pages in vfree() relies on nr_pages of struct vm_struct. vmap() does not update nr_pages. It can lead to memory leaks. Fixes: ddaf29fd9bb6 ("firmware: Free temporary page table after vmapping") Signed-off-by: Prateek Sood Reviewed-by: Takashi Iwai Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/1597957070-27185-1-git-send-email-prsood@codeaurora.org Signed-off-by: Greg Kroah-Hartman