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Driver core fixes for 5.18-rc7

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Here is one fix, and 3 documentation updates for 5.18-rc7.
 
 The fix is for the firmware loader which resolves a long-reported
 problem where the credentials of the firmware loader could be set to a
 userspace process without enough permissions to actually load the
 firmware image.  Many Android vendors have been reporting this for quite
 some time.
 
 The documentation updates are for the embargoed-hardware-issues.rst file
 to add a new entry, change an existing one, and sort the list to make
 changes easier in the future.
 
 All of these have been in linux-next for a while with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-5.18-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core fixes from Greg KH:
 "Here is one fix, and three documentation updates for 5.18-rc7.

  The fix is for the firmware loader which resolves a long-reported
  problem where the credentials of the firmware loader could be set to a
  userspace process without enough permissions to actually load the
  firmware image. Many Android vendors have been reporting this for
  quite some time.

  The documentation updates are for the embargoed-hardware-issues.rst
  file to add a new entry, change an existing one, and sort the list to
  make changes easier in the future.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'driver-core-5.18-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  Documentation/process: Update ARM contact for embargoed hardware issues
  Documentation/process: Add embargoed HW contact for Ampere Computing
  Documentation/process: Make groups alphabetical and use tabs consistently
  firmware_loader: use kernel credentials when reading firmware
This commit is contained in:
Linus Torvalds 2022-05-15 08:08:51 -07:00
commit 0cdd776ec9
2 changed files with 21 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
Documentation/process/embargoed-hardware-issues.rst
View File

@ -244,10 +244,11 @@ disclosure of a particular issue, unless requested by a response team or by
an involved disclosed party. The current ambassadors list:
============= ========================================================
ARM Grant Likely <grant.likely@arm.com>
AMD Tom Lendacky <tom.lendacky@amd.com>
IBM Z Christian Borntraeger <borntraeger@de.ibm.com>
IBM Power Anton Blanchard <anton@linux.ibm.com>
Ampere Darren Hart <darren@os.amperecomputing.com>
ARM Catalin Marinas <catalin.marinas@arm.com>
IBM Power Anton Blanchard <anton@linux.ibm.com>
IBM Z Christian Borntraeger <borntraeger@de.ibm.com>
Intel Tony Luck <tony.luck@intel.com>
Qualcomm Trilok Soni <tsoni@codeaurora.org>

17
drivers/base/firmware_loader/main.c
View File

@ -735,6 +735,8 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
size_t offset, u32 opt_flags)
{
struct firmware *fw = NULL;
struct cred *kern_cred = NULL;
const struct cred *old_cred;
bool nondirect = false;
int ret;
@ -751,6 +753,18 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
if (ret <= 0) /* error or already assigned */
goto out;
/*
* We are about to try to access the firmware file. Because we may have been
* called by a driver when serving an unrelated request from userland, we use
* the kernel credentials to read the file.
*/
kern_cred = prepare_kernel_cred(NULL);
if (!kern_cred) {
ret = -ENOMEM;
goto out;
}
old_cred = override_creds(kern_cred);
ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL);
/* Only full reads can support decompression, platform, and sysfs. */
@ -776,6 +790,9 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
} else
ret = assign_fw(fw, device);
revert_creds(old_cred);
put_cred(kern_cred);
out:
if (ret < 0) {
fw_abort_batch_reqs(fw);