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author | 2016-02-08 14:48:15 -0500 | |
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committer | 2016-02-10 16:25:52 +0000 | |
commit | ed8b0de5a33d2a2557dce7f9429dca8cb5bc5879 (patch) | |
tree | 1dcd2e49cc432ae312677ec47453ec3abc18f1d2 /tools/testing/selftests/efivarfs/open-unlink.c | |
parent | efi: Make our variable validation list include the guid (diff) | |
download | linux-ed8b0de5a33d2a2557dce7f9429dca8cb5bc5879.tar.gz linux-ed8b0de5a33d2a2557dce7f9429dca8cb5bc5879.tar.bz2 linux-ed8b0de5a33d2a2557dce7f9429dca8cb5bc5879.zip |
efi: Make efivarfs entries immutable by default
"rm -rf" is bricking some peoples' laptops because of variables being
used to store non-reinitializable firmware driver data that's required
to POST the hardware.
These are 100% bugs, and they need to be fixed, but in the mean time it
shouldn't be easy to *accidentally* brick machines.
We have to have delete working, and picking which variables do and don't
work for deletion is quite intractable, so instead make everything
immutable by default (except for a whitelist), and make tools that
aren't quite so broad-spectrum unset the immutable flag.
Signed-off-by: Peter Jones <pjones@redhat.com>
Tested-by: Lee, Chun-Yi <jlee@suse.com>
Acked-by: Matthew Garrett <mjg59@coreos.com>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Diffstat (limited to 'tools/testing/selftests/efivarfs/open-unlink.c')
-rw-r--r-- | tools/testing/selftests/efivarfs/open-unlink.c | 72 |
1 files changed, 71 insertions, 1 deletions
diff --git a/tools/testing/selftests/efivarfs/open-unlink.c b/tools/testing/selftests/efivarfs/open-unlink.c index 8c0764407b3c..4af74f733036 100644 --- a/tools/testing/selftests/efivarfs/open-unlink.c +++ b/tools/testing/selftests/efivarfs/open-unlink.c @@ -1,10 +1,68 @@ +#include <errno.h> #include <stdio.h> #include <stdint.h> #include <stdlib.h> #include <unistd.h> +#include <sys/ioctl.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> +#include <linux/fs.h> + +static int set_immutable(const char *path, int immutable) +{ + unsigned int flags; + int fd; + int rc; + int error; + + fd = open(path, O_RDONLY); + if (fd < 0) + return fd; + + rc = ioctl(fd, FS_IOC_GETFLAGS, &flags); + if (rc < 0) { + error = errno; + close(fd); + errno = error; + return rc; + } + + if (immutable) + flags |= FS_IMMUTABLE_FL; + else + flags &= ~FS_IMMUTABLE_FL; + + rc = ioctl(fd, FS_IOC_SETFLAGS, &flags); + error = errno; + close(fd); + errno = error; + return rc; +} + +static int get_immutable(const char *path) +{ + unsigned int flags; + int fd; + int rc; + int error; + + fd = open(path, O_RDONLY); + if (fd < 0) + return fd; + + rc = ioctl(fd, FS_IOC_GETFLAGS, &flags); + if (rc < 0) { + error = errno; + close(fd); + errno = error; + return rc; + } + close(fd); + if (flags & FS_IMMUTABLE_FL) + return 1; + return 0; +} int main(int argc, char **argv) { @@ -27,7 +85,7 @@ int main(int argc, char **argv) buf[4] = 0; /* create a test variable */ - fd = open(path, O_WRONLY | O_CREAT); + fd = open(path, O_WRONLY | O_CREAT, 0600); if (fd < 0) { perror("open(O_WRONLY)"); return EXIT_FAILURE; @@ -41,6 +99,18 @@ int main(int argc, char **argv) close(fd); + rc = get_immutable(path); + if (rc < 0) { + perror("ioctl(FS_IOC_GETFLAGS)"); + return EXIT_FAILURE; + } else if (rc) { + rc = set_immutable(path, 0); + if (rc < 0) { + perror("ioctl(FS_IOC_SETFLAGS)"); + return EXIT_FAILURE; + } + } + fd = open(path, O_RDONLY); if (fd < 0) { perror("open"); |