Messages in this thread Patch in this message | | | From | Chao Yu <> | Subject | [PATCH v2] f2fs: fix use-after-free issue | Date | Fri, 24 Jul 2020 09:38:11 +0800 |
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From: Li Guifu <bluce.liguifu@huawei.com>
During umount, f2fs_put_super() unregisters procfs entries after f2fs_destroy_segment_manager(), it may cause use-after-free issue when umount races with procfs accessing, fix it by relocating f2fs_unregister_sysfs().
[Chao Yu: change commit title/message a bit]
Signed-off-by: Li Guifu <bluce.liguifu@huawei.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> --- v2: - fix typo in commit message. - improve comment in f2fs_put_super() a bit. fs/f2fs/super.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 80cb7cd358f8..5e0a3eeb8ca4 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1175,6 +1175,9 @@ static void f2fs_put_super(struct super_block *sb) int i; bool dropped; + /* unregister procfs/sysfs entries in advance to avoid race case */ + f2fs_unregister_sysfs(sbi); + f2fs_quota_off_umount(sb); /* prevent remaining shrinker jobs */ @@ -1240,8 +1243,6 @@ static void f2fs_put_super(struct super_block *sb) kvfree(sbi->ckpt); - f2fs_unregister_sysfs(sbi); - sb->s_fs_info = NULL; if (sbi->s_chksum_driver) crypto_free_shash(sbi->s_chksum_driver); -- 2.26.2
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