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| author | Christian Brauner <christian.brauner@ubuntu.com> | 2021-01-21 14:19:56 +0100 |
|---|---|---|
| committer | Christian Brauner <christian.brauner@ubuntu.com> | 2021-01-24 14:43:46 +0100 |
| commit | 4b78993681083361f19f66b4e9db298945647a3d (patch) | |
| tree | 8da220e6162c1d5326f0f468d5b32e2e5b42022b /net/netfilter/nft_queue.c | |
| parent | 01eadc8dd96d7215dda71a1fe74b07b0e3b48af5 (diff) | |
| download | linux-4b78993681083361f19f66b4e9db298945647a3d.tar.bz2 | |
fat: handle idmapped mounts
Let fat handle idmapped mounts. This allows to have the same fat mount
appear in multiple locations with different id mappings. This allows to
expose a vfat formatted USB stick to multiple user with different ids on
the host or in user namespaces allowing for dac permissions:
mount -o uid=1000,gid=1000 /dev/sdb /mnt
u1001@f2-vm:/lower1$ ls -ln /mnt/
total 4
-rwxr-xr-x 1 1000 1000 4 Oct 28 03:44 aaa
-rwxr-xr-x 1 1000 1000 0 Oct 28 01:09 bbb
-rwxr-xr-x 1 1000 1000 0 Oct 28 01:10 ccc
-rwxr-xr-x 1 1000 1000 0 Oct 28 03:46 ddd
-rwxr-xr-x 1 1000 1000 0 Oct 28 04:01 eee
mount-idmapped --map-mount b:1000:1001:1
u1001@f2-vm:/lower1$ ls -ln /lower1/
total 4
-rwxr-xr-x 1 1001 1001 4 Oct 28 03:44 aaa
-rwxr-xr-x 1 1001 1001 0 Oct 28 01:09 bbb
-rwxr-xr-x 1 1001 1001 0 Oct 28 01:10 ccc
-rwxr-xr-x 1 1001 1001 0 Oct 28 03:46 ddd
-rwxr-xr-x 1 1001 1001 0 Oct 28 04:01 eee
u1001@f2-vm:/lower1$ touch /lower1/fff
u1001@f2-vm:/lower1$ ls -ln /lower1/fff
-rwxr-xr-x 1 1001 1001 0 Oct 28 04:03 /lower1/fff
u1001@f2-vm:/lower1$ ls -ln /mnt/fff
-rwxr-xr-x 1 1000 1000 0 Oct 28 04:03 /mnt/fff
Link: https://lore.kernel.org/r/20210121131959.646623-38-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Diffstat (limited to 'net/netfilter/nft_queue.c')
0 files changed, 0 insertions, 0 deletions