mount: handle OOM on mnt_warn_timestamp_expiry

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: f8b92ba67c ("mount: Add mount warning for impending timestamp expiry")
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Link: https://lore.kernel.org/r/20240730085856.32385-1-olaf@aepfle.de
[brauner: rewrite commit and commit message]
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Olaf Hering 2024-07-30 10:58:13 +02:00 committed by Christian Brauner
parent de7007f27d
commit 4bcda1eaf1

View File

@ -2921,8 +2921,15 @@ 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,
@ -2930,8 +2937,9 @@ 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);
}
}