linux-kernel - [PATCH] f2fs: don't call iput() from f2fs_drop

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250930232957.14361-1-mjguzik@gmail.com>
Date: Wed,  1 Oct 2025 01:29:57 +0200
From: Mateusz Guzik <mjguzik@...il.com>
To: brauner@...nel.org
Cc: linux-kernel@...r.kernel.org,
	linux-fsdevel@...r.kernel.org,
	josef@...icpanda.com,
	oe-lkp@...ts.linux.dev,
	linux-f2fs-devel@...ts.sourceforge.net,
	ltp@...ts.linux.it,
	oliver.sang@...el.com,
	Mateusz Guzik <mjguzik@...il.com>
Subject: [PATCH] f2fs: don't call iput() from f2fs_drop_inode()

iput() calls the problematic routine, which does a ->i_count inc/dec
cycle. Undoing it with iput() recurses into the problem.

Note f2fs should not be playing games with the refcount to begin with,
but that will be handled later. Right now solve the immediate
regression.

Fixes: bc986b1d756482a ("fs: stop accessing ->i_count directly in f2fs and gfs2")
Reported-by: kernel test robot <oliver.sang@...el.com>
Closes: https://lore.kernel.org/oe-lkp/202509301450.138b448f-lkp@intel.com
Signed-off-by: Mateusz Guzik <mjguzik@...il.com>
---
 fs/f2fs/super.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 2619cbbd7d2d..26ec31eb8c80 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1769,7 +1769,7 @@ static int f2fs_drop_inode(struct inode *inode)
 			sb_end_intwrite(inode->i_sb);
 
 			spin_lock(&inode->i_lock);
-			iput(inode);
+			atomic_dec(&inode->i_count);
 		}
 		trace_f2fs_drop_inode(inode, 0);
 		return 0;
-- 
2.43.0