[PATCH 1/6] firmware: permit LSMs and IMA to fail firmware sysfs fallback loading
From: Mimi Zohar <hidden>
Date: 2018-05-01 13:48:45
Also in:
linux-integrity, lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, filesystems (vfs and infrastructure), firmware loader (request_firmware), the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Alexander Viro, Christian Brauner, Luis Chamberlain, Russ Weight, Linus Torvalds
Add an LSM hook prior to allowing firmware sysfs fallback loading. Signed-off-by: Mimi Zohar <redacted> Cc: Luis R. Rodriguez <redacted> Cc: David Howells <dhowells@redhat.com> Cc: Kees Cook <redacted> Cc: Matthew Garrett <redacted> --- drivers/base/firmware_loader/fallback.c | 7 +++++++ include/linux/fs.h | 1 + 2 files changed, 8 insertions(+)
diff --git a/drivers/base/firmware_loader/fallback.c b/drivers/base/firmware_loader/fallback.c
index 31b5015b59fe..23d2af30474e 100644
--- a/drivers/base/firmware_loader/fallback.c
+++ b/drivers/base/firmware_loader/fallback.c@@ -651,6 +651,8 @@ static bool fw_force_sysfs_fallback(unsigned int opt_flags) static bool fw_run_sysfs_fallback(unsigned int opt_flags) { + int ret; + if (fw_fallback_config.ignore_sysfs_fallback) { pr_info_once("Ignoring firmware sysfs fallback due to sysctl knob\n"); return false;
@@ -659,6 +661,11 @@ static bool fw_run_sysfs_fallback(unsigned int opt_flags) if ((opt_flags & FW_OPT_NOFALLBACK)) return false; + /* Also permit LSMs and IMA to fail firmware sysfs fallback */ + ret = security_kernel_read_file(NULL, READING_FIRMWARE_FALLBACK); + if (ret < 0) + return ret; + return fw_force_sysfs_fallback(opt_flags); }
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 760d8da1b6c7..dc16a73c3d38 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h@@ -2810,6 +2810,7 @@ extern int do_pipe_flags(int *, int); id(UNKNOWN, unknown) \ id(FIRMWARE, firmware) \ id(FIRMWARE_PREALLOC_BUFFER, firmware) \ + id(FIRMWARE_FALLBACK, firmware) \ id(MODULE, kernel-module) \ id(KEXEC_IMAGE, kexec-image) \ id(KEXEC_INITRAMFS, kexec-initramfs) \
--
2.7.5
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