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| author | Sven Van Asbroeck <thesven73@gmail.com> | 2019-06-17 14:23:54 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-21 09:03:03 +0200 |
| commit | 244db54441a110906d770f777d78abffa732b915 (patch) | |
| tree | c81e47c1c106de5eb3007e54efa9bcb154059cfc /drivers/base | |
| parent | 079d7f16a9738f8ea8a71671f5481f9b5049da3a (diff) | |
| download | linux-stable-244db54441a110906d770f777d78abffa732b915.tar.gz linux-stable-244db54441a110906d770f777d78abffa732b915.tar.bz2 linux-stable-244db54441a110906d770f777d78abffa732b915.zip | |
firmware: improve LSM/IMA security behaviour
commit 2472d64af2d3561954e2f05365a67692bb852f2a upstream.
The firmware loader queries if LSM/IMA permits it to load firmware
via the sysfs fallback. Unfortunately, the code does the opposite:
it expressly permits sysfs fw loading if security_kernel_load_data(
LOADING_FIRMWARE) returns -EACCES. This happens because a
zero-on-success return value is cast to a bool that's true on success.
Fix the return value handling so we get the correct behaviour.
Fixes: 6e852651f28e ("firmware: add call to LSM hook before firmware sysfs fallback")
Cc: Stable <stable@vger.kernel.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Kees Cook <keescook@chromium.org>
To: Luis Chamberlain <mcgrof@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sven Van Asbroeck <TheSven73@gmail.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/firmware_loader/fallback.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c index b5c865fe263b..818d8c37d70a 100644 --- a/drivers/base/firmware_loader/fallback.c +++ b/drivers/base/firmware_loader/fallback.c @@ -659,7 +659,7 @@ static bool fw_run_sysfs_fallback(enum fw_opt opt_flags) /* Also permit LSMs and IMA to fail firmware sysfs fallback */ ret = security_kernel_load_data(LOADING_FIRMWARE); if (ret < 0) - return ret; + return false; return fw_force_sysfs_fallback(opt_flags); } |