kernel/linux.git/fs/debugfs/inode.c, branch v5.10.258

debugfs: fix automount d_fsdata usage

2024-01-25T22:37:36+00:00

[ Upstream commit 0ed04a1847a10297595ac24dc7d46b35fb35f90a ] debugfs_create_automount() stores a function pointer in d_fsdata, but since commit 7c8d469877b1 ("debugfs: add support for more elaborate ->d_fsdata") debugfs_release_dentry() will free it, now conditionally on DEBUGFS_FSDATA_IS_REAL_FOPS_BIT, but that's not set for the function pointer in automount. As a result, removing an automount dentry would attempt to free the function pointer. Luckily, the only user of this (tracing) never removes it. Nevertheless, it's safer if we just handle the fsdata in one way, namely either DEBUGFS_FSDATA_IS_REAL_FOPS_BIT or allocated. Thus, change the automount to allocate it, and use the real_fops in the data to indicate whether or not automount is filled, rather than adding a type tag. At least for now this isn't actually needed, but the next changes will require it. Also check in debugfs_file_get() that it gets only called on regular files, just to make things clearer. Acked-by: Greg Kroah-Hartman Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin

debugfs: add debugfs_lookup_and_remove()

2022-09-15T09:32:03+00:00

commit dec9b2f1e0455a151a7293c367da22ab973f713e upstream. There is a very common pattern of using debugfs_remove(debufs_lookup(..)) which results in a dentry leak of the dentry that was looked up. Instead of having to open-code the correct pattern of calling dput() on the dentry, create debugfs_lookup_and_remove() to handle this pattern automatically and properly without any memory leaks. Cc: stable Reported-by: Kuyo Chang Tested-by: Kuyo Chang Link: https://lore.kernel.org/r/YxIaQ8cSinDR881k@kroah.com Signed-off-by: Greg Kroah-Hartman

debugfs: debugfs_create_file_size(): use IS_ERR to check for error

2021-10-06T13:55:59+00:00

commit af505cad9567f7a500d34bf183696d570d7f6810 upstream. debugfs_create_file() returns encoded error so use IS_ERR for checking return value. Reviewed-by: Christian König Signed-off-by: Nirmoy Das Fixes: ff9fb72bc077 ("debugfs: return error values, not NULL") Cc: stable References: https://gitlab.freedesktop.org/drm/amd/-/issues/1686 Link: https://lore.kernel.org/r/20210902102917.2233-1-nirmoy.das@amd.com Signed-off-by: Greg Kroah-Hartman

debugfs: Make debugfs_allow RO after init

2021-05-19T08:13:19+00:00

commit 312723a0b34d6d110aa4427a982536bb36ab8471 upstream. Since debugfs_allow is only set at boot time during __init, make it read-only after being set. Fixes: a24c6f7bc923 ("debugfs: Add access restriction option") Cc: Peter Enderborg Reviewed-by: Peter Enderborg Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20210405213959.3079432-1-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman

debugfs: do not attempt to create a new file before the filesystem is initalized

2021-03-04T10:37:17+00:00

commit 56348560d495d2501e87db559a61de717cd3ab02 upstream. Some subsystems want to add debugfs files at early boot, way before debugfs is initialized. This seems to work somehow as the vfs layer will not allow it to happen, but let's be explicit and test to ensure we are properly up and running before allowing files to be created. Cc: "Rafael J. Wysocki" Cc: stable Reported-by: Michael Walle Reported-by: Marc Zyngier Link: https://lore.kernel.org/r/20210218100818.3622317-2-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

debugfs: be more robust at handling improper input in debugfs_lookup()

2021-03-04T10:37:17+00:00

commit bc6de804d36b3709d54fa22bd128cbac91c11526 upstream. debugfs_lookup() doesn't like it if it is passed an illegal name pointer, or if the filesystem isn't even initialized yet. If either of these happen, it will crash the system, so fix it up by properly testing for valid input and that we are up and running before trying to find a file in the filesystem. Cc: "Rafael J. Wysocki" Cc: stable Reported-by: Michael Walle Tested-by: Michael Walle Tested-by: Marc Zyngier Link: https://lore.kernel.org/r/20210218100818.3622317-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

debugfs: Add access restriction option

2020-07-23T15:10:25+00:00

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 Link: https://lore.kernel.org/r/20200716071511.26864-3-peter.enderborg@sony.com Signed-off-by: Greg Kroah-Hartman

debugfs: remove return value of debugfs_create_file_size()

2020-03-18T12:35:29+00:00

No one checks the return value of debugfs_create_file_size, as it's not needed, so make the return value void, so that no one tries to do so in the future. Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20200309163640.237984-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman

Merge branch 'work.recursive_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2020-02-05T05:09:46+00:00

Pull vfs recursive removal updates from Al Viro: "We have quite a few places where synthetic filesystems do an equivalent of 'rm -rf', with varying amounts of code duplication, wrong locking, etc. That really ought to be a library helper. Only debugfs (and very similar tracefs) are converted here - I have more conversions, but they'd never been in -next, so they'll have to wait" * 'work.recursive_removal' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: simple_recursive_removal(): kernel-side rm -rf for ramfs-style filesystems

debugfs: Fix warnings when building documentation

2020-01-06T19:35:37+00:00

Fix the following warnings: fs/debugfs/inode.c:423: WARNING: Inline literal start-string without end-string. fs/debugfs/inode.c:502: WARNING: Inline literal start-string without end-string. fs/debugfs/inode.c:534: WARNING: Inline literal start-string without end-string. fs/debugfs/inode.c:627: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:496: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:502: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:581: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:587: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:846: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:852: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:899: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:905: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:1091: WARNING: Inline literal start-string without end-string. fs/debugfs/file.c:1097: WARNING: Inline literal start-string without end-string By replacing %ERR_PTR with ERR_PTR. Signed-off-by: Daniel W. S. Almeida Link: https://lore.kernel.org/r/20191227010035.854913-1-dwlsalmeida@gmail.com Signed-off-by: Greg Kroah-Hartman