mirror of
https://github.com/RGBCube/serenity
synced 2025-07-25 15:57:45 +00:00
Kernel: Support read-only filesystem mounts
This adds support for MS_RDONLY, a mount flag that tells the kernel to disallow any attempts to write to the newly mounted filesystem. As this flag is per-mount, and different mounts of the same filesystems (such as in case of bind mounts) can have different mutability settings, you have to go though a custody to find out if the filesystem is mounted read-only, instead of just asking the filesystem itself whether it's inherently read-only. This also adds a lot of checks we were previously missing; and moves some of them to happen after more specific checks (such as regular permission checks). One outstanding hole in this system is sys$mprotect(PROT_WRITE), as there's no way we can know if the original file description this region has been mounted from had been opened through a readonly mount point. Currently, we always allow such sys$mprotect() calls to succeed, which effectively allows anyone to circumvent the effect of MS_RDONLY. We should solve this one way or another.
This commit is contained in:
parent
b905126365
commit
fdb71cdf8f
6 changed files with 60 additions and 16 deletions
|
@ -54,6 +54,7 @@ public:
|
|||
String absolute_path() const;
|
||||
|
||||
int mount_flags() const { return m_mount_flags; }
|
||||
bool is_readonly() const;
|
||||
|
||||
private:
|
||||
Custody(Custody* parent, const StringView& name, Inode&, int mount_flags);
|
||||
|
|
Loading…
Add table
Add a link
Reference in a new issue