From: Chao Yu yuchao0@huawei.com
[ Upstream commit 62f63eea291b50a5677ae7503ac128803174698a ]
BUG: kernel NULL pointer dereference, address: 0000000000000000 RIP: 0010:f2fs_write_begin+0x823/0xb90 [f2fs] Call Trace: f2fs_quota_write+0x139/0x1d0 [f2fs] write_blk+0x36/0x80 [quota_tree] get_free_dqblk+0x42/0xa0 [quota_tree] do_insert_tree+0x235/0x4a0 [quota_tree] do_insert_tree+0x26e/0x4a0 [quota_tree] do_insert_tree+0x26e/0x4a0 [quota_tree] do_insert_tree+0x26e/0x4a0 [quota_tree] qtree_write_dquot+0x70/0x190 [quota_tree] v2_write_dquot+0x43/0x90 [quota_v2] dquot_acquire+0x77/0x100 f2fs_dquot_acquire+0x2f/0x60 [f2fs] dqget+0x310/0x450 dquot_transfer+0x7e/0x120 f2fs_setattr+0x11a/0x4a0 [f2fs] notify_change+0x349/0x480 chown_common+0x168/0x1c0 do_fchownat+0xbc/0xf0 __x64_sys_fchownat+0x20/0x30 do_syscall_64+0x5f/0x220 entry_SYSCALL_64_after_hwframe+0x44/0xa9
Passing fsdata parameter to .write_{begin,end} in f2fs_quota_write(), so that if quota file is compressed one, we can avoid above NULL pointer dereference when updating quota content.
Signed-off-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 da348cf..45f8f6e 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1648,6 +1648,7 @@ static ssize_t f2fs_quota_write(struct super_block *sb, int type, int offset = off & (sb->s_blocksize - 1); size_t towrite = len; struct page *page; + void *fsdata = NULL; char *kaddr; int err = 0; int tocopy; @@ -1657,7 +1658,7 @@ static ssize_t f2fs_quota_write(struct super_block *sb, int type, towrite); retry: err = a_ops->write_begin(NULL, mapping, off, tocopy, 0, - &page, NULL); + &page, &fsdata); if (unlikely(err)) { if (err == -ENOMEM) { congestion_wait(BLK_RW_ASYNC, HZ/50); @@ -1672,7 +1673,7 @@ static ssize_t f2fs_quota_write(struct super_block *sb, int type, flush_dcache_page(page);
a_ops->write_end(NULL, mapping, off, tocopy, tocopy, - page, NULL); + page, fsdata); offset = 0; towrite -= tocopy; off += tocopy;