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 12:56:59 -0700 |
| commit | e25cec3b76aba47a49138d2162fc809c6cd49c9e (patch) | |
| tree | fb3d7570750ac5083a9ac511655f4358566c101c | |
| parent | 0e464d5b6957e35abebcb6fd8e4321c4ae04f61f (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 8878b46589ff..cafadfe8e858 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); } |