Unverified Commit 49440290 authored Jan 10, 2025 by Mickaël Salaün

landlock: Handle weird files



A corrupted filesystem (e.g. bcachefs) might return weird files.
Instead of throwing a warning and allowing access to such file, treat
them as regular files.

Cc: Dave Chinner <david@fromorbit.com>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Paul Moore <paul@paul-moore.com>
Reported-by:  <syzbot+34b68f850391452207df@syzkaller.appspotmail.com>
Closes: https://lore.kernel.org/r/000000000000a65b35061cffca61@google.com


Reported-by:  <syzbot+360866a59e3c80510a62@syzkaller.appspotmail.com>
Closes: https://lore.kernel.org/r/67379b3f.050a0220.85a0.0001.GAE@google.com


Reported-by: Ubisectech Sirius <bugreport@ubisectech.com>
Closes: https://lore.kernel.org/r/c426821d-8380-46c4-a494-7008bbd7dd13.bugreport@ubisectech.com


Fixes: cb2c7d1a ("landlock: Support filesystem access-control")
Reviewed-by: Günther Noack <gnoack3000@gmail.com>
Link: https://lore.kernel.org/r/20250110153918.241810-1-mic@digikod.net


Signed-off-by: Mickaël Salaün <mic@digikod.net>

parent 078bf943

security/landlock/fs.c

+5 −6

Original line number	Diff line number	Diff line
		@@ -937,10 +937,6 @@ static access_mask_t get_mode_access(const umode_t mode)
		switch (mode & S_IFMT) {
		case S_IFLNK:
		return LANDLOCK_ACCESS_FS_MAKE_SYM;
		case 0:
		/* A zero mode translates to S_IFREG. */
		case S_IFREG:
		return LANDLOCK_ACCESS_FS_MAKE_REG;
		case S_IFDIR:
		return LANDLOCK_ACCESS_FS_MAKE_DIR;
		case S_IFCHR:
		@@ -951,9 +947,12 @@ static access_mask_t get_mode_access(const umode_t mode)
		return LANDLOCK_ACCESS_FS_MAKE_FIFO;
		case S_IFSOCK:
		return LANDLOCK_ACCESS_FS_MAKE_SOCK;
		case S_IFREG:
		case 0:
		/* A zero mode translates to S_IFREG. */
		default:
		WARN_ON_ONCE(1);
		return 0;
		/* Treats weird files as regular files. */
		return LANDLOCK_ACCESS_FS_MAKE_REG;
		}
		}