6.1-stable review patch. If anyone has any objections, please let me know.
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From: Ryusuke Konishi konishi.ryusuke@gmail.com
[ Upstream commit 602ce7b8e1343b19c0cf93a3dd1926838ac5a1cc ]
If nilfs2 reads a corrupted disk image and its DAT metadata file contains invalid lifetime data for a virtual block number, a kernel warning can be generated by the WARN_ON check in nilfs_dat_commit_end() and can panic if the kernel is booted with panic_on_warn.
This patch avoids the issue with a sanity check that treats it as an error.
Since error return is not allowed in the execution phase of nilfs_dat_commit_end(), this inserts that sanity check in nilfs_dat_prepare_end(), which prepares for nilfs_dat_commit_end().
As the error code, -EINVAL is returned to notify bmap layer of the metadata corruption. When the bmap layer sees this code, it handles the abnormal situation and replaces the return code with -EIO as it should.
Link: https://lkml.kernel.org/r/000000000000154d2c05e9ec7df6@google.com Link: https://lkml.kernel.org/r/20230127132202.6083-1-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi konishi.ryusuke@gmail.com Reported-by: syzbot+cbff7a52b6f99059e67f@syzkaller.appspotmail.com Tested-by: Ryusuke Konishi konishi.ryusuke@gmail.com Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/nilfs2/dat.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/fs/nilfs2/dat.c b/fs/nilfs2/dat.c index 242cc36bf1e97..351010828d883 100644 --- a/fs/nilfs2/dat.c +++ b/fs/nilfs2/dat.c @@ -158,6 +158,7 @@ void nilfs_dat_commit_start(struct inode *dat, struct nilfs_palloc_req *req, int nilfs_dat_prepare_end(struct inode *dat, struct nilfs_palloc_req *req) { struct nilfs_dat_entry *entry; + __u64 start; sector_t blocknr; void *kaddr; int ret; @@ -169,6 +170,7 @@ int nilfs_dat_prepare_end(struct inode *dat, struct nilfs_palloc_req *req) kaddr = kmap_atomic(req->pr_entry_bh->b_page); entry = nilfs_palloc_block_get_entry(dat, req->pr_entry_nr, req->pr_entry_bh, kaddr); + start = le64_to_cpu(entry->de_start); blocknr = le64_to_cpu(entry->de_blocknr); kunmap_atomic(kaddr);
@@ -179,6 +181,15 @@ int nilfs_dat_prepare_end(struct inode *dat, struct nilfs_palloc_req *req) return ret; } } + if (unlikely(start > nilfs_mdt_cno(dat))) { + nilfs_err(dat->i_sb, + "vblocknr = %llu has abnormal lifetime: start cno (= %llu) > current cno (= %llu)", + (unsigned long long)req->pr_entry_nr, + (unsigned long long)start, + (unsigned long long)nilfs_mdt_cno(dat)); + nilfs_dat_abort_entry(dat, req); + return -EINVAL; + }
return 0; }