From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8159D340298; Sat, 30 May 2026 18:30:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780165803; cv=none; b=rqK9dGcDQ+mYHLKf7ZwmXKHZ7L+mdDAhwUcfMDIaBvFnc65E+0G81i2c4TqbHMYaZg2/wjNQfU7y0uy1wWAYXn9MaUh1oKxxgW59xws3EXHu/YKVBZrgVofUZd6FpqffvLyez3GysFhCnz8Q3awuBAf2E3O/79klJTCaZAyZhZc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780165803; c=relaxed/simple; bh=9gei/AP9OxzLMBrXkpZb9xkN0F81DXxTWnXquFEqlag=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WqqGfX2h4PDIiN6oYOegae7UXvsAtfFzavW96GimGcuS112orfo1lzIYwWjk89x+w2v7AWGwhlQ+W/4FyKceqfX8+EAXZNlc8R3TMdG4Q0IT/ltJEfC9HlDqf6c/yO4+OPFJdD3XscYV+5z/63nlZApuQEh1GshjJ9gYJzRY9xo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fiOSWn9u; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="fiOSWn9u" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0494C1F00893; Sat, 30 May 2026 18:30:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780165802; bh=FDl9A3hi/YIDng5Ql8PJjyrv0tjVjQqvdeZ5BWRdSk4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fiOSWn9uN+j4CvZj5CKzYL/nETLf4vUwmmaRk9zMtSMpZFtKBH2pkAVXOZ6l7BY1L THkd6onkyNQiZiP5Zx8wsNeN2m7+tBXSxKbnGi6/ang0qJR3vXNP2JW+8XjHY8Ztxj TntNYUBssbUhytxDZTZuT89fSmbFrk/DeeimC0/M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chia-Ming Chang , robbieko , Nikolay Borisov , Jan Kara Subject: [PATCH 5.10 187/589] inotify: fix watch count leak when fsnotify_add_inode_mark_locked() fails Date: Sat, 30 May 2026 18:01:08 +0200 Message-ID: <20260530160229.803988125@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160224.570625122@linuxfoundation.org> References: <20260530160224.570625122@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chia-Ming Chang commit 6a320935fa4293e9e599ec9f85dc9eb3be7029f8 upstream. When fsnotify_add_inode_mark_locked() fails in inotify_new_watch(), the error path calls inotify_remove_from_idr() but does not call dec_inotify_watches() to undo the preceding inc_inotify_watches(). This leaks a watch count, and repeated failures can exhaust the max_user_watches limit with -ENOSPC even when no watches are active. Prior to commit 1cce1eea0aff ("inotify: Convert to using per-namespace limits"), the watch count was incremented after fsnotify_add_mark_locked() succeeded, so this path was not affected. The conversion moved inc_inotify_watches() before the mark insertion without adding the corresponding rollback. Add the missing dec_inotify_watches() call in the error path. Fixes: 1cce1eea0aff ("inotify: Convert to using per-namespace limits") Cc: stable@vger.kernel.org Signed-off-by: Chia-Ming Chang Signed-off-by: robbieko Reviewed-by: Nikolay Borisov Link: https://patch.msgid.link/20260224093442.3076294-1-chiamingc@synology.com Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman --- fs/notify/inotify/inotify_user.c | 1 + 1 file changed, 1 insertion(+) --- a/fs/notify/inotify/inotify_user.c +++ b/fs/notify/inotify/inotify_user.c @@ -609,6 +609,7 @@ static int inotify_new_watch(struct fsno if (ret) { /* we failed to get on the inode, get off the idr */ inotify_remove_from_idr(group, tmp_i_mark); + dec_inotify_watches(group->inotify_data.ucounts); goto out_err; }