kernel/linux.git/fs/afs, branch v7.1.8

afs: Fix UAF when sending a message

2026-08-09T18:26:43+00:00

commit 4af1ec68d54b3871155914d584fb10669c41a861 upstream. In afs_make_call(), there's a race with async call reception and destruction. If a call is dispatched that doesn't have call->write_iter set (used to specify the data content for FS.StoreData), then the first rxrpc_kernel_send_data() will not set MSG_MORE in the msghdr. Once rxrpc_send_data() queues the last request packet, the response could come in at any time and cause the call to be completed and put. However, afs_make_call() will look at the call again to see it ->write_iter should be handled - something it's only allowed to do if it has its own ref on the call. Whilst this is the case for synchronous calls, it isn't true for async calls such as FS.FetchData. There's also a potential UAF in afs_make_call() in the event that an asynchronous call is being sent, but the call fails in some way (e.g. it gets aborted from the server). The problem there is that afs_make_call() tries to abort a call if the rxrpc send fails, but the asynchronous notification from rxrpc may have caused the afs_call to be torn down. generic/650 plays games with randomly taking CPUs offline, and can interject a significant delay such that the call is deallocated before afs_make_call() gets to check call->write_iter - and a UAF ensues (caught by KASAN). BUG: KASAN: slab-use-after-free in afs_make_call+0x1c90/0x2210 [kafs] Read of size 8 at addr ffff888035e050e8 by task fsstress/1409 Fix this by making afs_make_op_call() give the op->call its own ref rather than transferring the caller's ref to it and then dropping the ref when afs_make_call() returns. This also means that the afs_make_call() func never loses its ref on the call now. Fixes: eddf51f2bb2c ("afs: Make {Y,}FS.FetchData an asynchronous operation") Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept") Link: https://sashiko.dev/#/patchset/20260702144919.172295-1-dhowells%40redhat.com Reported-by: Marc Dionne Signed-off-by: David Howells Link: https://patch.msgid.link/20260723113452.566619-4-dhowells@redhat.com cc: Jeffrey Altman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Greg Kroah-Hartman

afs: Fix afs_fs_fetch_data() to subtract transferred from len

2026-08-09T18:26:43+00:00

commit 222052c6be186f2074b3a4d741d5de200f654c43 upstream. Fix afs_fs_fetch_data() to subtract subreq->transferred from subreq->len rather than adding it. Fixes: f28fc2010d62 ("afs: Eliminate afs_read") Link: https://sashiko.dev/#/patchset/20260713081022.2186481-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260723113452.566619-3-dhowells@redhat.com cc: Marc Dionne cc: Jeffrey Altman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Greg Kroah-Hartman

afs: Fix afs_fs_fetch_data() to set call->async

2026-08-09T18:26:42+00:00

commit d568a43f6dbba3ba006304d95fd09862bd482a2f upstream. Fix afs_fs_fetch_data() to set call->async on an async operation as does afs_fs_fetch_data64(). Fixes: eddf51f2bb2c ("afs: Make {Y,}FS.FetchData an asynchronous operation") Link: https://sashiko.dev/#/patchset/20260702144919.172295-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260723113452.566619-2-dhowells@redhat.com cc: Marc Dionne cc: Jeffrey Altman cc: linux-afs@lists.infradead.org cc: stable@kernel.org Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Greg Kroah-Hartman

afs: Fix afs_edit_dir_remove() to get, not find, block 0

2026-08-03T09:25:54+00:00

commit 62d9853aa4ce6e9797b6949804891be14b219752 upstream. Fix afs_edit_dir_remove() to use afs_dir_get_block() to get block 0 rather than afs_dir_find_block() as the latter caches the found block in the afs_dir_iter and may[*] switch out the page it's on if another afs_dir_find_block() is done. This parallels what afs_edit_dir_add() does. [*] There's more than one block per page. Fixes: a5b5beebcf96 ("afs: Use the contained hashtable to search a directory") Closes: https://sashiko.dev/#/patchset/20260706153408.1231650-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/2380759.1783956175@warthog.procyon.org.uk cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: linux-fsdevel@vger.kernel.org cc: stable@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Greg Kroah-Hartman

afs: Fix unchecked-length string display in debug statement

2026-07-24T14:20:37+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

2026-07-24T14:20:37+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 premature cell exposure through /afs

2026-07-24T14:20:37+00:00

[ Upstream commit 26f17ce6fa3f05cb5965790499c1839094260de4 ] AFS cell records are prematurely exposured through the /afs dynamic root by virtue of adding them immediately to the net->cells_dyn_ino IDR when the cell is allocated rather than when it is added to the lookup tree. This allows a candidate record to be accessed, even if it's actually a duplicate or not published yet. Fix this by not adding the cell to cells_dyn_ino until it's confirmed non-duplicate and is being published. A flag is then used to record whether it is added to the IDR to make removal from the IDR conditional. Closes: https://sashiko.dev/#/patchset/20260618155141.2513212-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260622090856.2746629-20-dhowells@redhat.com Fixes: 1d0b929fc070 ("afs: Change dynroot to create contents on demand") cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Sasha Levin

afs: Fix lack of locking around modifications of net->cells_dyn_ino

2026-07-24T14:20:37+00:00

[ Upstream commit 55e841836c6f4646490f7b0347192b7a92d431ba ] Fix the lack of locking around modifications of net->cells_dyn_ino by taking net->cells_lock exclusively. This also requires to cell to be removed from net->cells_dyn_ino in afs_destroy_cell_work() rather than in afs_cell_destroy() as the latter runs in RCU cleanup context and sleeping locks cannot be taken there. Fixes: 1d0b929fc070 ("afs: Change dynroot to create contents on demand") Closes: https://sashiko.dev/#/patchset/20260618074903.2374756-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260622090856.2746629-19-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

2026-07-24T14:20:37+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 leak of ungot volume

2026-07-24T14:20:37+00:00

[ Upstream commit d672c276f685a540ed2b2a8bafaed4650a89022c ] Fix afs_lookup_volume_rcu() so that it doesn't leak a dying volume if afs_try_get_volume() fails. Fixes: 32222f09782f ("afs: Apply server breaks to mmap'd files in the call processor") Closes: https://sashiko.dev/#/patchset/20260609081738.770127-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260622090856.2746629-17-dhowells@redhat.com cc: Marc Dionne cc: Deepakkumar Karn cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Sasha Levin