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| author | Peter Enderborg <peter.enderborg@sony.com> | 2020-07-16 10:15:11 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-23 18:10:25 +0300 |
| commit | a24c6f7bc923d5e2f3139855eb09b0d480d6b410 (patch) | |
| tree | f96b6939d66e6cb438690706dcb76b7e2a948f73 /fs/debugfs/internal.h | |
| parent | 072e133d554bb74929f902582c8cf66d9fd12771 (diff) | |
| download | linux-a24c6f7bc923d5e2f3139855eb09b0d480d6b410.tar.xz | |
debugfs: Add access restriction option
Since debugfs include sensitive information it need to be treated
carefully. But it also has many very useful debug functions for userspace.
With this option we can have same configuration for system with
need of debugfs and a way to turn it off. This gives a extra protection
for exposure on systems where user-space services with system
access are attacked.
It is controlled by a configurable default value that can be override
with a kernel command line parameter. (debugfs=)
It can be on or off, but also internally on but not seen from user-space.
This no-mount mode do not register a debugfs as filesystem, but client can
register their parts in the internal structures. This data can be readed
with a debugger or saved with a crashkernel. When it is off clients
get EPERM error when accessing the functions for registering their
components.
Signed-off-by: Peter Enderborg <peter.enderborg@sony.com>
Link: https://lore.kernel.org/r/20200716071511.26864-3-peter.enderborg@sony.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/debugfs/internal.h')
| -rw-r--r-- | fs/debugfs/internal.h | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/fs/debugfs/internal.h b/fs/debugfs/internal.h index 034e6973cead..92af8ae31313 100644 --- a/fs/debugfs/internal.h +++ b/fs/debugfs/internal.h @@ -29,4 +29,18 @@ struct debugfs_fsdata { */ #define DEBUGFS_FSDATA_IS_REAL_FOPS_BIT BIT(0) +/* Access BITS */ +#define DEBUGFS_ALLOW_API BIT(0) +#define DEBUGFS_ALLOW_MOUNT BIT(1) + +#ifdef CONFIG_DEBUG_FS_ALLOW_ALL +#define DEFAULT_DEBUGFS_ALLOW_BITS (DEBUGFS_ALLOW_MOUNT | DEBUGFS_ALLOW_API) +#endif +#ifdef CONFIG_DEBUG_FS_DISALLOW_MOUNT +#define DEFAULT_DEBUGFS_ALLOW_BITS (DEBUGFS_ALLOW_API) +#endif +#ifdef CONFIG_DEBUG_FS_ALLOW_NONE +#define DEFAULT_DEBUGFS_ALLOW_BITS (0) +#endif + #endif /* _DEBUGFS_INTERNAL_H_ */ |