From: Deepanshu Kartikey Date: Wed, 10 Dec 2025 13:28:07 +0000 (+0530) Subject: btrfs: fix memory leak of fs_devices in degraded seed device path X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b57f2ddd28737db6ff0e9da8467f0ab9d707e997;p=thirdparty%2Fkernel%2Flinux.git btrfs: fix memory leak of fs_devices in degraded seed device path In open_seed_devices(), when find_fsid() fails and we're in DEGRADED mode, a new fs_devices is allocated via alloc_fs_devices() but is never added to the seed_list before returning. This contrasts with the normal path where fs_devices is properly added via list_add(). If any error occurs later in read_one_dev() or btrfs_read_chunk_tree(), the cleanup code iterates seed_list to free seed devices, but this orphaned fs_devices is never found and never freed, causing a memory leak. Any devices allocated via add_missing_dev() and attached to this fs_devices are also leaked. Fix this by adding the newly allocated fs_devices to seed_list in the degraded path, consistent with the normal path. Fixes: 5f37583569442 ("Btrfs: move the missing device to its own fs device list") Reported-by: syzbot+eadd98df8bceb15d7fed@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=eadd98df8bceb15d7fed Tested-by: syzbot+eadd98df8bceb15d7fed@syzkaller.appspotmail.com Reviewed-by: Qu Wenruo Signed-off-by: Deepanshu Kartikey Reviewed-by: David Sterba Signed-off-by: David Sterba --- diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index e81c8ac0d8ae..e35872149e2f 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -7131,6 +7131,7 @@ static struct btrfs_fs_devices *open_seed_devices(struct btrfs_fs_info *fs_info, fs_devices->seeding = true; fs_devices->opened = 1; + list_add(&fs_devices->seed_list, &fs_info->fs_devices->seed_list); return fs_devices; }