Patch "cachefiles: add missing lock protection when polling" has been added to the 6.6-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This is a note to let you know that I've just added the patch titled

    cachefiles: add missing lock protection when polling

to the 6.6-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     cachefiles-add-missing-lock-protection-when-polling.patch
and it can be found in the queue-6.6 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 16af081c22c2594547ac77a16ae52aa8a8ef9c1c
Author: Jingbo Xu <jefflexu@xxxxxxxxxxxxxxxxx>
Date:   Fri Jun 28 14:29:30 2024 +0800

    cachefiles: add missing lock protection when polling
    
    [ Upstream commit cf5bb09e742a9cf6349127e868329a8f69b7a014 ]
    
    Add missing lock protection in poll routine when iterating xarray,
    otherwise:
    
    Even with RCU read lock held, only the slot of the radix tree is
    ensured to be pinned there, while the data structure (e.g. struct
    cachefiles_req) stored in the slot has no such guarantee.  The poll
    routine will iterate the radix tree and dereference cachefiles_req
    accordingly.  Thus RCU read lock is not adequate in this case and
    spinlock is needed here.
    
    Fixes: b817e22b2e91 ("cachefiles: narrow the scope of triggering EPOLLIN events in ondemand mode")
    Signed-off-by: Jingbo Xu <jefflexu@xxxxxxxxxxxxxxxxx>
    Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20240628062930.2467993-10-libaokun@xxxxxxxxxxxxxxx
    Acked-by: Jeff Layton <jlayton@xxxxxxxxxx>
    Reviewed-by: Jia Zhu <zhujia.zj@xxxxxxxxxxxxx>
    Reviewed-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
    Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/cachefiles/daemon.c b/fs/cachefiles/daemon.c
index 06cdf1a8a16f6..89b11336a8369 100644
--- a/fs/cachefiles/daemon.c
+++ b/fs/cachefiles/daemon.c
@@ -366,14 +366,14 @@ static __poll_t cachefiles_daemon_poll(struct file *file,
 
 	if (cachefiles_in_ondemand_mode(cache)) {
 		if (!xa_empty(&cache->reqs)) {
-			rcu_read_lock();
+			xas_lock(&xas);
 			xas_for_each_marked(&xas, req, ULONG_MAX, CACHEFILES_REQ_NEW) {
 				if (!cachefiles_ondemand_is_reopening_read(req)) {
 					mask |= EPOLLIN;
 					break;
 				}
 			}
-			rcu_read_unlock();
+			xas_unlock(&xas);
 		}
 	} else {
 		if (test_bit(CACHEFILES_STATE_CHANGED, &cache->flags))




[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux