kernel/linux.git/fs/afs, branch v6.12.97

afs: Fix afs_dynroot_readdir() to not use the RCU read lock

2026-07-24T14:11:55+00:00

commit a64e4d48a0b77e4ada19ac26ca3a08cd492f6362 upstream. afs_dynroot_readdir() uses the RCU read lock to walk the cell list whilst emitting cell automount entries - but dir_emit() may write to a userspace buffer, thereby causing a fault to occur and waits to happen. Fix afs_dynroot_readdir() to get a shared lock on net->cells_lock instead. This can be triggered by enabling lockdep, preconfiguring a number of cells, doing "mount -t afs none /afs -o dyn" (or using the kafs-client package with afs.mount systemd unit enabled) and then doing "ls /afs". Fixes: 1d0b929fc070 ("afs: Change dynroot to create contents on demand") Reported-by: syzbot+3b6c5c6a1d0119b687a1@syzkaller.appspotmail.com Reported-by: syzbot+8245611446194a52150d@syzkaller.appspotmail.com Reported-by: syzbot+1aa62e6852a6ad1c7944@syzkaller.appspotmail.com Reported-by: syzbot+54e6c2176ba76c56217e@syzkaller.appspotmail.com Signed-off-by: David Howells Link: https://lore.kernel.org/1638014.1744145189@warthog.procyon.org.uk cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

afs: Fix afs_atcell_get_link() to check if ws_cell is unset first

2026-07-24T14:11:55+00:00

commit 0307d16f3610eb29ad0b7529846de7d62fed60ca upstream. Fix afs_atcell_get_link() to check if the workstation cell is unset before doing the RCU pathwalk bit where we dereference that. Fixes: 823869e1e616 ("afs: Fix afs_atcell_get_link() to handle RCU pathwalk") Reported-by: syzbot+76a6f18e3af82e84f264@syzkaller.appspotmail.com Signed-off-by: David Howells Link: https://lore.kernel.org/r/2481796.1742296819@warthog.procyon.org.uk Tested-by: syzbot+76a6f18e3af82e84f264@syzkaller.appspotmail.com cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman

netfs: Drop the error arg from netfs_read_subreq_terminated()

2026-07-24T14:11:21+00:00

[ Upstream commit 360157829ee3dba848ffa817792d9a07969e0a95 ] Drop the error argument from netfs_read_subreq_terminated() in favour of passing the value in subreq->error. Signed-off-by: David Howells Link: https://lore.kernel.org/r/20241216204124.3752367-9-dhowells@redhat.com cc: Jeff Layton cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner Stable-dep-of: c16b8c4cfb4f ("cifs: Fix missing credit release on failure in cifs_issue_read()") Signed-off-by: Sasha Levin

afs: Fix unchecked-length string display in debug statement

2026-07-24T14:11:21+00:00

[ Upstream commit 903d37c97228258da71e092f8b4ab260ce81497d ] Fix afs_extract_vlserver_list() to limit the length of the displayed string in a debug statement(). Fixes: 0a5143f2f89c ("afs: Implement VL server rotation") Closes: https://sashiko.dev/#/patchset/20260618074903.2374756-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260622090856.2746629-22-dhowells@redhat.com cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Sasha Levin

afs: Fix the volume AFS_VOLUME_RM_TREE is set on

2026-07-24T14:11:21+00:00

[ Upstream commit 56b4e4b26f84411d880f968a539207b0a8889c8c ] Fix afs_insert_volume_into_cell() to set AFS_VOLUME_RM_TREE on the volume replaced, not the new volume, as it's now removed from the cell's volume tree. This will cause the old volume to be removed from the tree twice and the new volume never to be removed. Fixes: 9a6b294ab496 ("afs: Fix use-after-free due to get/remove race in volume tree") Closes: https://sashiko.dev/#/patchset/20260618074903.2374756-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260622090856.2746629-21-dhowells@redhat.com cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Sasha Levin

afs: Fix vllist leak

2026-07-24T14:11:21+00:00

[ Upstream commit fc10c0ecf06f2981af5d04357612b00051e03e9e ] Fix a leak of the new vllist in afs_update_cell() in the event that it is an empty list (nr_servers == 0), in which case the old list isn't displaced unless the old list is also empty. Fixes: d5c32c89b208 ("afs: Fix cell DNS lookup") Closes: https://sashiko.dev/#/patchset/20260609081738.770127-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260622090856.2746629-18-dhowells@redhat.com cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Sasha Levin

afs: Fix missing NULL pointer check in afs_break_some_callbacks()

2026-07-24T14:11:21+00:00

[ Upstream commit 794a01110390c1b76f59ece773fb0fbfd89c6f5c ] Fix afs_break_some_callbacks() to check to see if afs_lookup_volume_rcu() returned NULL (e.g. the specified volume is unknown). Fixes: 8230fd8217b7 ("afs: Make callback processing more efficient.") Closes: https://sashiko.dev/#/patchset/20260609081738.770127-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260622090856.2746629-16-dhowells@redhat.com cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Sasha Levin

afs: Fix callback service message parsers to pass through -EAGAIN

2026-07-24T14:11:21+00:00

[ Upstream commit 0f36469d7ce98b362934113c550d08bb0c784231 ] The AFS filesystem client uses an rxrpc server to listen for callback notifications. Each callback call type handler has a delivery function that parses the incoming request stream, and this should return -EAGAIN the last packet hasn't yet been seen, but all currently queued received data is consumed. afs_extract_data() does this, but the -EAGAIN return is switched to 0 inadvertantly Fix callback service message parsers to pass through -EAGAIN Fixes: d001648ec7cf ("rxrpc: Don't expose skbs to in-kernel users [ver #2]") Closes: https://sashiko.dev/#/patchset/20260609081738.770127-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260622090856.2746629-14-dhowells@redhat.com cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Sasha Levin

afs: Fix misplaced inc of net->cells_outstanding

2026-07-24T14:11:21+00:00

[ Upstream commit c9c3b615a462a4023bd148f02c564e175ed10502 ] Fix net->cells_outstanding being incremented before the check for failure of idr_alloc_cyclic(), leaving the count incremented on error. Fixes: 88c853c3f5c0 ("afs: Fix cell refcounting by splitting the usage counter") Reported-by: Hillf Danton Signed-off-by: David Howells Link: https://patch.msgid.link/20260622090856.2746629-12-dhowells@redhat.com cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Sasha Levin

afs: Change dynroot to create contents on demand

2026-07-24T14:11:21+00:00

[ Upstream commit 1d0b929fc070b4115403a0a6206a0c6a62dd61f5 ] Change the AFS dynamic root to do things differently: (1) Rather than having the creation of cell records create inodes and dentries for cell mountpoints, create them on demand during lookup. This simplifies cell management and locking as we no longer have to create these objects in advance *and* on speculative lookup by the user for a cell that isn't precreated. (2) Rather than using the libfs dentry-based readdir (the dentries now no longer exist until accessed from (1)), have readdir generate the contents by reading the list of cells. The @cell symlinks get pushed in positions 2 and 3 if rootcell has been configured. (3) Make the @cell symlink dentries persist for the life of the superblock or until reclaimed, but make cell mountpoints disappear immediately if unused. It's not perfect as someone doing an "ls -l /afs" may create a whole bunch of dentries which will be garbage collected immediately. But any dentry that gets automounted will be pinned by the mount, so it shouldn't be too bad. (4) Allocate the inode numbers for the cell mountpoints from an IDR to prevent duplicates appearing in the event it cycles round. The number allocated from the IDR is doubled to provide two inode numbers - one for the normal cell name (RO) and one for the dotted cell name (RW). Signed-off-by: David Howells cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org Link: https://lore.kernel.org/r/20250224234154.2014840-8-dhowells@redhat.com/ # v1 Link: https://lore.kernel.org/r/20250310094206.801057-4-dhowells@redhat.com/ # v4 Stable-dep-of: c9c3b615a462 ("afs: Fix misplaced inc of net->cells_outstanding") Signed-off-by: Sasha Levin