linux

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Christian Brauner a2966e0436 ovl: check type and offset of struct vfsmount in ovl_entry

[ Upstream commit f723edb8a532cd26e1ff0a2b271d73762d48f762 ]

Porting overlayfs to the new amount api I started experiencing random
crashes that couldn't be explained easily. So after much debugging and
reasoning it became clear that struct ovl_entry requires the point to
struct vfsmount to be the first member and of type struct vfsmount.

During the port I added a new member at the beginning of struct
ovl_entry which broke all over the place in the form of random crashes
and cache corruptions. While there's a comment in ovl_free_fs() to the
effect of "Hack! Reuse ofs->layers as a vfsmount array before freeing
it" there's no such comment on struct ovl_entry which makes this easy to
trip over.

Add a comment and two static asserts for both the offset and the type of
pointer in struct ovl_entry.

Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

2023-08-26 15:26:44 +02:00

copy_up.c

ovl: update of dentry revalidate flags after copy up

2023-07-27 08:43:55 +02:00

dir.c

ovl: update of dentry revalidate flags after copy up

2023-07-27 08:43:55 +02:00

export.c

ovl: update of dentry revalidate flags after copy up

2023-07-27 08:43:55 +02:00

file.c

ovl: remove privs in ovl_fallocate()