syzbot has uncovered a class of lockdep false positives for
setups with sysfs being one of the backing layers in overlayfs.
The root cause is that of->mutex allocated when opening
a sysfs file read-only (which overlayfs might do) is confused
with of->mutex of a file opened writable (held in write to sysfs
file, which overlayfs won't do).
Assigning them separate lockdep classes fixes that bunch and it's
obviously safe.
The following changes since commit fec50db7033ea478773b159e0e2efb135270e3b7:
Linux 6.9-rc3 (2024-04-07 13:22:46 -0700)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs.git tags/pull-sysfs-annotation-fix
for you to fetch changes up to 16b52bbee4823b01ab7fe3919373c981a38f3797:
kernfs: annotate different lockdep class for of->mutex of writable files (2024-04-14 06:55:46 -0400)
----------------------------------------------------------------
Get rid of lockdep false positives around sysfs/overlayfs
----------------------------------------------------------------
Amir Goldstein (1):
kernfs: annotate different lockdep class for of->mutex of writable files
fs/kernfs/file.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
