From bb7a72d0093fa63d008f8d650aad7d7102c4c24f Mon Sep 17 00:00:00 2001 From: Olaf Hering Date: Tue, 30 Jul 2024 10:58:13 +0200 Subject: [PATCH] mount: handle OOM on mnt_warn_timestamp_expiry [ Upstream commit 4bcda1eaf184e308f07f9c61d3a535f9ce477ce8 ] If no page could be allocated, an error pointer was used as format string in pr_warn. Rearrange the code to return early in case of OOM. Also add a check for the return value of d_path. Fixes: f8b92ba67c5d ("mount: Add mount warning for impending timestamp expiry") Signed-off-by: Olaf Hering Link: https://lore.kernel.org/r/20240730085856.32385-1-olaf@aepfle.de [brauner: rewrite commit and commit message] Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin --- fs/namespace.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index e6c61d4997ccf..b4385e2413d59 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2796,8 +2796,15 @@ static void mnt_warn_timestamp_expiry(struct path *mountpoint, struct vfsmount * if (!__mnt_is_readonly(mnt) && (!(sb->s_iflags & SB_I_TS_EXPIRY_WARNED)) && (ktime_get_real_seconds() + TIME_UPTIME_SEC_MAX > sb->s_time_max)) { - char *buf = (char *)__get_free_page(GFP_KERNEL); - char *mntpath = buf ? d_path(mountpoint, buf, PAGE_SIZE) : ERR_PTR(-ENOMEM); + char *buf, *mntpath; + + buf = (char *)__get_free_page(GFP_KERNEL); + if (buf) + mntpath = d_path(mountpoint, buf, PAGE_SIZE); + else + mntpath = ERR_PTR(-ENOMEM); + if (IS_ERR(mntpath)) + mntpath = "(unknown)"; pr_warn("%s filesystem being %s at %s supports timestamps until %ptTd (0x%llx)\n", sb->s_type->name, @@ -2805,8 +2812,9 @@ static void mnt_warn_timestamp_expiry(struct path *mountpoint, struct vfsmount * mntpath, &sb->s_time_max, (unsigned long long)sb->s_time_max); - free_page((unsigned long)buf); sb->s_iflags |= SB_I_TS_EXPIRY_WARNED; + if (buf) + free_page((unsigned long)buf); } }