The patch titled
Subject: procfs: fix a locking bug in a vmcore_add_device_dump() error path
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
procfs-fix-a-locking-bug-in-a-vmcore_add_device_dump-error-path.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/procfs-fix-a-locking-bug-in-a-vmcore_add_device_dump-error-path.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Bart Van Assche <bvanassche@xxxxxxx>
Subject: procfs: fix a locking bug in a vmcore_add_device_dump() error path
Date: Wed, 29 Jan 2025 14:20:03 -0800
Unlock vmcore_mutex when returning -EBUSY.
Link: https://lkml.kernel.org/r/20250129222003.1495713-1-bvanassche@xxxxxxx
Fixes: 0f3b1c40c652 ("fs/proc/vmcore: disallow vmcore modifications while the vmcore is open")
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Baoquan he <bhe@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/vmcore.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/fs/proc/vmcore.c~procfs-fix-a-locking-bug-in-a-vmcore_add_device_dump-error-path
+++ a/fs/proc/vmcore.c
@@ -1524,7 +1524,7 @@ int vmcore_add_device_dump(struct vmcore
pr_warn_once("Unexpected adding of device dump\n");
if (vmcore_open) {
ret = -EBUSY;
- goto out_err;
+ goto unlock;
}
list_add_tail(&dump->list, &vmcoredd_list);
@@ -1532,6 +1532,9 @@ int vmcore_add_device_dump(struct vmcore
mutex_unlock(&vmcore_mutex);
return 0;
+unlock:
+ mutex_unlock(&vmcore_mutex);
+
out_err:
vfree(buf);
vfree(dump);
_
Patches currently in -mm which might be from bvanassche@xxxxxxx are
procfs-fix-a-locking-bug-in-a-vmcore_add_device_dump-error-path.patch
