| 51dc4111 | 18-Feb-2025 |
David Howells <dhowells@redhat.com> |
afs: Fix the server_list to unuse a displaced server rather than putting it
[ Upstream commit add117e48df4788a86a21bd0515833c0a6db1ad1 ]
When allocating and building an afs_server_list struct objec
afs: Fix the server_list to unuse a displaced server rather than putting it
[ Upstream commit add117e48df4788a86a21bd0515833c0a6db1ad1 ]
When allocating and building an afs_server_list struct object from a VLDB
record, we look up each server address to get the server record for it -
but a server may have more than one entry in the record and we discard the
duplicate pointers. Currently, however, when we discard, we only put a
server record, not unuse it - but the lookup got as an active-user count.
The active-user count on an afs_server_list object determines its lifetime
whereas the refcount keeps the memory backing it around. Failing to reduce
the active-user counter prevents the record from being cleaned up and can
lead to multiple copied being seen - and pointing to deleted afs_cell
objects and other such things.
Fix this by switching the incorrect 'put' to an 'unuse' instead.
Without this, occasionally, a dead server record can be seen in
/proc/net/afs/servers and list corruption may be observed:
list_del corruption. prev->next should be ffff888102423e40, but was 0000000000000000. (prev=ffff88810140cd38)
Fixes: 977e5f8ed0ab ("afs: Split the usage count on struct afs_server")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
Link: https://patch.msgid.link/20250218192250.296870-5-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| a5e15707 | 16-Dec-2024 |
David Howells <dhowells@redhat.com> |
afs: Fix cleanup of immediately failed async calls
[ Upstream commit 9750be93b2be12b6d92323b97d7c055099d279e6 ]
If we manage to begin an async call, but fail to transmit any data on it
due to a sig
afs: Fix cleanup of immediately failed async calls
[ Upstream commit 9750be93b2be12b6d92323b97d7c055099d279e6 ]
If we manage to begin an async call, but fail to transmit any data on it
due to a signal, we then abort it which causes a race between the
notification of call completion from rxrpc and our attempt to cancel the
notification. The notification will be necessary, however, for async
FetchData to terminate the netfs subrequest.
However, since we get a notification from rxrpc upon completion of a call
(aborted or otherwise), we can just leave it to that.
This leads to calls not getting cleaned up, but appearing in
/proc/net/rxrpc/calls as being aborted with code 6.
Fix this by making the "error_do_abort:" case of afs_make_call() abort the
call and then abandon it to the notification handler.
Fixes: 34fa47612bfe ("afs: Fix race in async call refcounting")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-25-dhowells@redhat.com
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| 7e8ea8e8 | 16-Dec-2024 |
David Howells <dhowells@redhat.com> |
afs: Fix directory format encoding struct
[ Upstream commit 07a10767853adcbdbf436dc91393b729b52c4e81 ]
The AFS directory format structure, union afs_xdr_dir_block::meta, has too
many alloc counter
afs: Fix directory format encoding struct
[ Upstream commit 07a10767853adcbdbf436dc91393b729b52c4e81 ]
The AFS directory format structure, union afs_xdr_dir_block::meta, has too
many alloc counter slots declared and so pushes the hash table along and
over the data. This doesn't cause a problem at the moment because I'm
currently ignoring the hash table and only using the correct number of
alloc_ctrs in the code anyway. In future, however, I should start using
the hash table to try and speed up afs_lookup().
Fix this by using the correct constant to declare the counter array.
Fixes: 4ea219a839bf ("afs: Split the directory content defs into a header")
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-14-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| 08ade0fa | 30-Nov-2023 |
Oleg Nesterov <oleg@redhat.com> |
afs: fix the usage of read_seqbegin_or_lock() in afs_find_server*()
[ Upstream commit 1702e0654ca9a7bcd7c7619c8a5004db58945b71 ]
David Howells says:
(5) afs_find_server().
There could be a
afs: fix the usage of read_seqbegin_or_lock() in afs_find_server*()
[ Upstream commit 1702e0654ca9a7bcd7c7619c8a5004db58945b71 ]
David Howells says:
(5) afs_find_server().
There could be a lot of servers in the list and each server can have
multiple addresses, so I think this would be better with an exclusive
second pass.
The server list isn't likely to change all that often, but when it does
change, there's a good chance several servers are going to be
added/removed one after the other. Further, this is only going to be
used for incoming cache management/callback requests from the server,
which hopefully aren't going to happen too often - but it is remotely
drivable.
(6) afs_find_server_by_uuid().
Similarly to (5), there could be a lot of servers to search through, but
they are in a tree not a flat list, so it should be faster to process.
Again, it's not likely to change that often and, again, when it does
change it's likely to involve multiple changes. This can be driven
remotely by an incoming cache management request but is mostly going to
be driven by setting up or reconfiguring a volume's server list -
something that also isn't likely to happen often.
Make the "seq" counter odd on the 2nd pass, otherwise read_seqbegin_or_lock()
never takes the lock.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://lore.kernel.org/r/20231130115614.GA21581@redhat.com/
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| c3215484 | 21-Dec-2023 |
David Howells <dhowells@redhat.com> |
afs: Fix use-after-free due to get/remove race in volume tree
[ Upstream commit 9a6b294ab496650e9f270123730df37030911b55 ]
When an afs_volume struct is put, its refcount is reduced to 0 before
the
afs: Fix use-after-free due to get/remove race in volume tree
[ Upstream commit 9a6b294ab496650e9f270123730df37030911b55 ]
When an afs_volume struct is put, its refcount is reduced to 0 before
the cell->volume_lock is taken and the volume removed from the
cell->volumes tree.
Unfortunately, this means that the lookup code can race and see a volume
with a zero ref in the tree, resulting in a use-after-free:
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 3 PID: 130782 at lib/refcount.c:25 refcount_warn_saturate+0x7a/0xda
...
RIP: 0010:refcount_warn_saturate+0x7a/0xda
...
Call Trace:
afs_get_volume+0x3d/0x55
afs_create_volume+0x126/0x1de
afs_validate_fc+0xfe/0x130
afs_get_tree+0x20/0x2e5
vfs_get_tree+0x1d/0xc9
do_new_mount+0x13b/0x22e
do_mount+0x5d/0x8a
__do_sys_mount+0x100/0x12a
do_syscall_64+0x3a/0x94
entry_SYSCALL_64_after_hwframe+0x62/0x6a
Fix this by:
(1) When putting, use a flag to indicate if the volume has been removed
from the tree and skip the rb_erase if it has.
(2) When looking up, use a conditional ref increment and if it fails
because the refcount is 0, replace the node in the tree and set the
removal flag.
Fixes: 20325960f875 ("afs: Reorganise volume and server trees to be rooted on the cell")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| 81fc8dce | 21-Dec-2023 |
David Howells <dhowells@redhat.com> |
afs: Fix overwriting of result of DNS query
[ Upstream commit a9e01ac8c5ff32669119c40dfdc9e80eb0b7d7aa ]
In afs_update_cell(), ret is the result of the DNS lookup and the errors
are to be handled b
afs: Fix overwriting of result of DNS query
[ Upstream commit a9e01ac8c5ff32669119c40dfdc9e80eb0b7d7aa ]
In afs_update_cell(), ret is the result of the DNS lookup and the errors
are to be handled by a switch - however, the value gets clobbered in
between by setting it to -ENOMEM in case afs_alloc_vlserver_list()
fails.
Fix this by moving the setting of -ENOMEM into the error handling for
OOM failure. Further, only do it if we don't have an alternative error
to return.
Found by Linux Verification Center (linuxtesting.org) with SVACE. Based
on a patch from Anastasia Belova [1].
Fixes: d5c32c89b208 ("afs: Fix cell DNS lookup")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: Anastasia Belova <abelova@astralinux.ru>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: lvc-project@linuxtesting.org
Link: https://lore.kernel.org/r/20231221085849.1463-1-abelova@astralinux.ru/ [1]
Link: https://lore.kernel.org/r/1700862.1703168632@warthog.procyon.org.uk/ # v1
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| 3c305aa9 | 11-Dec-2023 |
David Howells <dhowells@redhat.com> |
afs: Fix dynamic root lookup DNS check
[ Upstream commit 74cef6872ceaefb5b6c5c60641371ea28702d358 ]
In the afs dynamic root directory, the ->lookup() function does a DNS check
on the cell being ask
afs: Fix dynamic root lookup DNS check
[ Upstream commit 74cef6872ceaefb5b6c5c60641371ea28702d358 ]
In the afs dynamic root directory, the ->lookup() function does a DNS check
on the cell being asked for and if the DNS upcall reports an error it will
report an error back to userspace (typically ENOENT).
However, if a failed DNS upcall returns a new-style result, it will return
a valid result, with the status field set appropriately to indicate the
type of failure - and in that case, dns_query() doesn't return an error and
we let stat() complete with no error - which can cause confusion in
userspace as subsequent calls that trigger d_automount then fail with
ENOENT.
Fix this by checking the status result from a valid dns_query() and
returning an error if it indicates a failure.
Fixes: bbb4c4323a4d ("dns: Allow the dns resolver to retrieve a server set")
Reported-by: Markus Suvanto <markus.suvanto@gmail.com>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=216637
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Markus Suvanto <markus.suvanto@gmail.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| ceca54f1 | 01-Nov-2023 |
David Howells <dhowells@redhat.com> |
afs: Fix file locking on R/O volumes to operate in local mode
[ Upstream commit b590eb41be766c5a63acc7e8896a042f7a4e8293 ]
AFS doesn't really do locking on R/O volumes as fileservers don't maintain
afs: Fix file locking on R/O volumes to operate in local mode
[ Upstream commit b590eb41be766c5a63acc7e8896a042f7a4e8293 ]
AFS doesn't really do locking on R/O volumes as fileservers don't maintain
state with each other and thus a lock on a R/O volume file on one
fileserver will not be be visible to someone looking at the same file on
another fileserver.
Further, the server may return an error if you try it.
Fix this by doing what other AFS clients do and handle filelocking on R/O
volume files entirely within the client and don't touch the server.
Fixes: 6c6c1d63c243 ("afs: Provide mount-time configurable byte-range file locking emulation")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| 18350d28 | 08-Jun-2023 |
David Howells <dhowells@redhat.com> |
afs: Make error on cell lookup failure consistent with OpenAFS
[ Upstream commit 2a4ca1b4b77850544408595e2433f5d7811a9daa ]
When kafs tries to look up a cell in the DNS or the local config, it will
afs: Make error on cell lookup failure consistent with OpenAFS
[ Upstream commit 2a4ca1b4b77850544408595e2433f5d7811a9daa ]
When kafs tries to look up a cell in the DNS or the local config, it will
translate a lookup failure into EDESTADDRREQ whereas OpenAFS translates it
into ENOENT. Applications such as West expect the latter behaviour and
fail if they see the former.
This can be seen by trying to mount an unknown cell:
# mount -t afs %example.com:cell.root /mnt
mount: /mnt: mount(2) system call failed: Destination address required.
Fixes: 4d673da14533 ("afs: Support the AFS dynamic root")
Reported-by: Markus Suvanto <markus.suvanto@gmail.com>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216637
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
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