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| author | Bernd Schubert <bschubert@ddn.com> | 2022-04-15 14:53:56 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-07-27 09:50:25 +0300 |
| commit | 549f5093e9d6d19d21dc4d5a763b7ec294a8af90 (patch) | |
| tree | e0b69e497241c75b6d1ce654a670fa262291a1ae | |
| parent | af6d1fc5b8a68c790e3da09ff5dfb61eff63cca0 (diff) | |
| download | linux-549f5093e9d6d19d21dc4d5a763b7ec294a8af90.tar.xz | |
fuse: Apply flags2 only when userspace set the FUSE_INIT_EXT
commit 3066ff93476c35679cb07a97cce37d9bb07632ff upstream.
This is just a safety precaution to avoid checking flags on memory that was
initialized on the user space side. libfuse zeroes struct fuse_init_out
outarg, but this is not guranteed to be done in all implementations.
Better is to act on flags and to only apply flags2 when FUSE_INIT_EXT is
set.
There is a risk with this change, though - it might break existing user
space libraries, which are already using flags2 without setting
FUSE_INIT_EXT.
The corresponding libfuse patch is here
https://github.com/libfuse/libfuse/pull/662
Signed-off-by: Bernd Schubert <bschubert@ddn.com>
Fixes: 53db28933e95 ("fuse: extend init flags")
Cc: <stable@vger.kernel.org> # v5.17
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/fuse/inode.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 6b3beda16c1b..bc3c3e76c646 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1127,7 +1127,10 @@ static void process_init_reply(struct fuse_mount *fm, struct fuse_args *args, process_init_limits(fc, arg); if (arg->minor >= 6) { - u64 flags = arg->flags | (u64) arg->flags2 << 32; + u64 flags = arg->flags; + + if (flags & FUSE_INIT_EXT) + flags |= (u64) arg->flags2 << 32; ra_pages = arg->max_readahead / PAGE_SIZE; if (flags & FUSE_ASYNC_READ) |