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([2405:201:682f:389d:62d5:79a:7a92:c774]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-35c03165c5esm626152a91.14.2026.03.23.20.40.04 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 23 Mar 2026 20:40:07 -0700 (PDT) From: Deepanshu Kartikey To: agruenba@redhat.com, willy@infradead.org Cc: gfs2@lists.linux.dev, linux-kernel@vger.kernel.org, Deepanshu Kartikey , syzbot+9013411dc43f3582823a@syzkaller.appspotmail.com, Deepanshu Kartikey Subject: [PATCH] gfs2: fix hung task in gfs2_jhead_process_page Date: Tue, 24 Mar 2026 09:09:59 +0530 Message-ID: <20260324033959.1456418-1-kartikey406@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: gfs2@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit filemap_get_folio() returns an ERR_PTR if the folio is not present in the page cache. gfs2_jhead_process_page() does not check the return value and passes it directly to folio_wait_locked(), causing the kernel task to get stuck in uninterruptible sleep (state D) forever, triggering the hung task watchdog. This can be triggered by mounting a crafted or corrupted GFS2 filesystem image. Fix this by checking the return value of filemap_get_folio() and returning early if the folio is not found. Fixes: 240159077d00 ("gfs2: Convert gfs2_jhead_process_page() to use a folio") Reported-by: syzbot+9013411dc43f3582823a@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9013411dc43f3582823a Signed-off-by: Deepanshu Kartikey --- fs/gfs2/lops.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c index 797931eb5845..005584311eff 100644 --- a/fs/gfs2/lops.c +++ b/fs/gfs2/lops.c @@ -467,6 +467,9 @@ static void gfs2_jhead_process_page(struct gfs2_jdesc *jd, unsigned long index, folio = filemap_get_folio(jd->jd_inode->i_mapping, index); + if (IS_ERR(folio)) + return; + folio_wait_locked(folio); if (!folio_test_uptodate(folio)) *done = true; -- 2.43.0