kernel/git/stable/linux.git/fs/afs, branch linux-5.5.y

rxrpc: Fix call interruptibility handling

2020-04-17T14:11:48+00:00

[ Upstream commit e138aa7d3271ac1b0690ae2c9b04d51468dce1d6 ] Fix the interruptibility of kernel-initiated client calls so that they're either only interruptible when they're waiting for a call slot to come available or they're not interruptible at all. Either way, they're not interruptible during transmission. This should help prevent StoreData calls from being interrupted when writeback is in progress. It doesn't, however, handle interruption during the receive phase. Userspace-initiated calls are still interruptable. After the signal has been handled, sendmsg() will return the amount of data copied out of the buffer and userspace can perform another sendmsg() call to continue transmission. Fixes: bc5e3a546d55 ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals") Signed-off-by: David Howells Signed-off-by: Sasha Levin

afs: Fix unpinned address list during probing

2020-04-01T09:00:15+00:00

commit 9efcc4a129363187c9bf15338692f107c5c9b6f0 upstream. When it's probing all of a fileserver's interfaces to find which one is best to use, afs_do_probe_fileserver() takes a lock on the server record and notes the pointer to the address list. It doesn't, however, pin the address list, so as soon as it drops the lock, there's nothing to stop the address list from being freed under us. Fix this by taking a ref on the address list inside the locked section and dropping it at the end of the function. Fixes: 3bf0fb6f33dd ("afs: Probe multiple fileservers simultaneously") Signed-off-by: David Howells Reviewed-by: Marc Dionne Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

afs: Fix some tracing details

2020-04-01T09:00:15+00:00

commit 4636cf184d6d9a92a56c2554681ea520dd4fe49a upstream. Fix a couple of tracelines to indicate the usage count after the atomic op, not the usage count before it to be consistent with other afs and rxrpc trace lines. Change the wording of the afs_call_trace_work trace ID label from "WORK" to "QUEUE" to reflect the fact that it's queueing work, not doing work. Fixes: 341f741f04be ("afs: Refcount the afs_call struct") Signed-off-by: David Howells Signed-off-by: Greg Kroah-Hartman

afs: Fix client call Rx-phase signal handling

2020-04-01T09:00:15+00:00

commit 7d7587db0d7fd1138f2afcffdc46a8e15630b944 upstream. Fix the handling of signals in client rxrpc calls made by the afs filesystem. Ignore signals completely, leaving call abandonment or connection loss to be detected by timeouts inside AF_RXRPC. Allowing a filesystem call to be interrupted after the entire request has been transmitted and an abort sent means that the server may or may not have done the action - and we don't know. It may even be worse than that for older servers. Fixes: bc5e3a546d55 ("rxrpc: Use MSG_WAITALL to tell sendmsg() to temporarily ignore signals") Signed-off-by: David Howells Signed-off-by: Greg Kroah-Hartman

afs: Fix handling of an abort from a service handler

2020-04-01T09:00:13+00:00

commit dde9f095583b3f375ba23979045ee10dfcebec2f upstream. When an AFS service handler function aborts a call, AF_RXRPC marks the call as complete - which means that it's not going to get any more packets from the receiver. This is a problem because reception of the final ACK is what triggers afs_deliver_to_call() to drop the final ref on the afs_call object. Instead, aborted AFS service calls may then just sit around waiting for ever or until they're displaced by a new call on the same connection channel or a connection-level abort. Fix this by calling afs_set_call_complete() to finalise the afs_call struct representing the call. However, we then need to drop the ref that stops the call from being deallocated. We can do this in afs_set_call_complete(), as the work queue is holding a separate ref of its own, but then we shouldn't do it in afs_process_async_call() and afs_delete_async_call(). call->drop_ref is set to indicate that a ref needs dropping for a call and this is dealt with when we transition a call to AFS_CALL_COMPLETE. But then we also need to get rid of the ref that pins an asynchronous client call. We can do this by the same mechanism, setting call->drop_ref for an async client call too. We can also get rid of call->incoming since nothing ever sets it and only one thing ever checks it (futilely). A trace of the rxrpc_call and afs_call struct ref counting looks like: -0 [001] ..s5 164.764892: rxrpc_call: c=00000002 SEE u=3 sp=rxrpc_new_incoming_call+0x473/0xb34 a=00000000442095b5 -0 [001] .Ns5 164.766001: rxrpc_call: c=00000002 QUE u=4 sp=rxrpc_propose_ACK+0xbe/0x551 a=00000000442095b5 -0 [001] .Ns4 164.766005: rxrpc_call: c=00000002 PUT u=3 sp=rxrpc_new_incoming_call+0xa3f/0xb34 a=00000000442095b5 -0 [001] .Ns7 164.766433: afs_call: c=00000002 WAKE u=2 o=11 sp=rxrpc_notify_socket+0x196/0x33c kworker/1:2-1810 [001] ...1 164.768409: rxrpc_call: c=00000002 SEE u=3 sp=rxrpc_process_call+0x25/0x7ae a=00000000442095b5 kworker/1:2-1810 [001] ...1 164.769439: rxrpc_tx_packet: c=00000002 e9f1a7a8:95786a88:00000008:09c5 00000001 00000000 02 22 ACK CallAck kworker/1:2-1810 [001] ...1 164.769459: rxrpc_call: c=00000002 PUT u=2 sp=rxrpc_process_call+0x74f/0x7ae a=00000000442095b5 kworker/1:2-1810 [001] ...1 164.770794: afs_call: c=00000002 QUEUE u=3 o=12 sp=afs_deliver_to_call+0x449/0x72c kworker/1:2-1810 [001] ...1 164.770829: afs_call: c=00000002 PUT u=2 o=12 sp=afs_process_async_call+0xdb/0x11e kworker/1:2-1810 [001] ...2 164.771084: rxrpc_abort: c=00000002 95786a88:00000008 s=0 a=1 e=1 K-1 kworker/1:2-1810 [001] ...1 164.771461: rxrpc_tx_packet: c=00000002 e9f1a7a8:95786a88:00000008:09c5 00000002 00000000 04 00 ABORT CallAbort kworker/1:2-1810 [001] ...1 164.771466: afs_call: c=00000002 PUT u=1 o=12 sp=SRXAFSCB_ProbeUuid+0xc1/0x106 The abort generated in SRXAFSCB_ProbeUuid(), labelled "K-1", indicates that the local filesystem/cache manager didn't recognise the UUID as its own. Fixes: 2067b2b3f484 ("afs: Fix the CB.ProbeUuid service handler to reply correctly") Signed-off-by: David Howells Signed-off-by: Greg Kroah-Hartman

afs: Fix characters allowed into cell names

2020-01-26T16:54:04+00:00

The afs filesystem needs to prohibit certain characters from cell names, such as '/', as these are used to form filenames in procfs, leading to the following warning being generated: WARNING: CPU: 0 PID: 3489 at fs/proc/generic.c:178 Fix afs_alloc_cell() to disallow nonprintable characters, '/', '@' and names that begin with a dot. Remove the check for "@cell" as that is then redundant. This can be tested by running: echo add foo/.bar 1.2.3.4 >/proc/fs/afs/cells Note that we will also need to deal with: - Names ending in ".invalid" shouldn't be passed to the DNS. - Names that contain non-valid domainname chars shouldn't be passed to the DNS. - DNS replies that say "your-dns-needs-immediate-attention." and replies containing A records that say 127.0.53.53 should be considered invalid. [https://www.icann.org/en/system/files/files/name-collision-mitigation-01aug14-en.pdf] but these need to be dealt with by the kafs-client DNS program rather than the kernel. Reported-by: syzbot+b904ba7c947a37b4b291@syzkaller.appspotmail.com Cc: stable@kernel.org Signed-off-by: David Howells Signed-off-by: Linus Torvalds

Merge branch 'dhowells' (patches from DavidH)

2020-01-14T17:56:31+00:00

Merge misc fixes from David Howells. Two afs fixes and a key refcounting fix. * dhowells: afs: Fix afs_lookup() to not clobber the version on a new dentry afs: Fix use-after-loss-of-ref keys: Fix request_key() cache

afs: Fix afs_lookup() to not clobber the version on a new dentry

2020-01-14T17:40:06+00:00

Fix afs_lookup() to not clobber the version set on a new dentry by afs_do_lookup() - especially as it's using the wrong version of the version (we need to use the one given to us by whatever op the dir contents correspond to rather than what's in the afs_vnode). Fixes: 9dd0b82ef530 ("afs: Fix missing dentry data version updating") Signed-off-by: David Howells Signed-off-by: Linus Torvalds

afs: Fix use-after-loss-of-ref

2020-01-14T17:40:06+00:00

afs_lookup() has a tracepoint to indicate the outcome of d_splice_alias(), passing it the inode to retrieve the fid from. However, the function gave up its ref on that inode when it called d_splice_alias(), which may have failed and dropped the inode. Fix this by caching the fid. Fixes: 80548b03991f ("afs: Add more tracepoints") Reported-by: Al Viro Signed-off-by: David Howells Signed-off-by: Linus Torvalds

afs: Show volume name in /proc/net/afs//volumes

2019-12-11T17:48:20+00:00

Show the name of each volume in /proc/net/afs//volumes to make it easier to work out the name corresponding to a volume ID. This makes it easier to work out which mounts in /proc/mounts correspond to which volume ID. Signed-off-by: David Howells Reviewed-by: Marc Dionne