diff options
| author | Max Kellermann <max.kellermann@ionos.com> | 2025-02-20 16:24:50 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-03-22 12:54:28 -0700 |
| commit | 62b9ad7e52d4777f7e775ee1f0ad2452f6041024 (patch) | |
| tree | dd04e76e3f03c1ffac9aaacbbce80e7d7881a424 | |
| parent | 8f324d99306b8fc5307901aa023c34c0879f81dd (diff) | |
fs/netfs/read_collect: add to next->prev_donated
If multiple subrequests donate data to the same "next" request
(depending on the subrequest completion order), each of them would
overwrite the `prev_donated` field, causing data corruption and a
BUG() crash ("Can't donate prior to front").
Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading")
Closes: https://lore.kernel.org/netfs/CAKPOu+_4mUwYgQtRTbXCmi+-k3PGvLysnPadkmHOyB7Gz0iSMA@mail.gmail.com/
Cc: stable@vger.kernel.org
Signed-off-by: Max Kellermann <max.kellermann@ionos.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/netfs/read_collect.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/netfs/read_collect.c b/fs/netfs/read_collect.c index 3b9461f5e712..eae415efae24 100644 --- a/fs/netfs/read_collect.c +++ b/fs/netfs/read_collect.c @@ -284,7 +284,7 @@ donation_changed: netfs_trace_donate_to_deferred_next); } else { next = list_next_entry(subreq, rreq_link); - WRITE_ONCE(next->prev_donated, excess); + WRITE_ONCE(next->prev_donated, next->prev_donated + excess); trace_netfs_donate(rreq, subreq, next, excess, netfs_trace_donate_to_next); } |