Re: [PATCH] fsnotify: add generic perm check for unlink/rmdir
From: Paul Moore <paul@paul-moore.com>
Date: 2022-05-18 01:17:24
Also in:
bpf, linux-fsdevel, linux-security-module, lkml, selinux
On Tue, May 3, 2022 at 2:38 PM Guowei Du [off-list ref] wrote:
From: duguowei <redacted> For now, there have been open/access/open_exec perms for file operation, so we add new perms check with unlink/rmdir syscall. if one app deletes any file/dir within pubic area, fsnotify can sends fsnotify_event to listener to deny that, even if the app have right dac/mac permissions. Signed-off-by: duguowei <redacted> --- fs/notify/fsnotify.c | 2 +- include/linux/fs.h | 2 ++ include/linux/fsnotify.h | 16 ++++++++++++++++ include/linux/fsnotify_backend.h | 6 +++++- security/security.c | 12 ++++++++++-- security/selinux/hooks.c | 4 ++++ 6 files changed, 38 insertions(+), 4 deletions(-)
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quoted hunk ↗ jump to hunk
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index e9e959343de9..f0780f0eb903 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c@@ -1801,8 +1801,12 @@ static int may_create(struct inode *dir, } #define MAY_LINK 0 +#ifndef MAY_UNLINK #define MAY_UNLINK 1 +#endif +#ifndef MAY_RMDIR #define MAY_RMDIR 2 +#endif
In the future if you run into a symbol collision here I would prefer if you renamed the SELinux constants to something like SEL_MAY_LINK, etc. -- paul-moore.com