nilfs2: propagate directory read errors from nilfs_find_entry()

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: nilfs2: propagate directory read errors from nilfs_find_entry() Syzbot reported that a task hang occurs in vcs_open() during a fuzzing test for nilfs2. The root cause of this problem is that in nilfs_find_entry(), which searches for directory entries, ignores errors when loading a directory page/folio via nilfs_get_folio() fails. If the filesystem images is corrupted, and the i_size of the directory inode is large, and the directory page/folio is successfully read but fails the sanity check, for example when it is zero-filled, nilfs_check_folio() may continue to spit out error messages in bursts. Fix this issue by propagating the error to the callers when loading a page/folio fails in nilfs_find_entry(). The current interface of nilfs_find_entry() and its callers is outdated and cannot propagate error codes such as -EIO and -ENOMEM returned via nilfs_find_entry(), so fix it together.

References

• https://git.kernel.org/stable/c/bb857ae1efd3138c653239ed1e7aef14e1242c81
• https://git.kernel.org/stable/c/b4b3dc9e7e604be98a222e9f941f5e93798ca475
• https://git.kernel.org/stable/c/c1d0476885d708a932980b0f28cd90d9bd71db39
• https://git.kernel.org/stable/c/edf8146057264191d5bfe5b91773f13d936dadd3
• https://git.kernel.org/stable/c/270a6f9df35fa2aea01ec23770dc9b3fc9a12989
• https://git.kernel.org/stable/c/9698088ac7704e260f492d9c254e29ed7dd8729a
• https://git.kernel.org/stable/c/efa810b15a25531cbc2f527330947b9fe16916e7
• https://git.kernel.org/stable/c/08cfa12adf888db98879dbd735bc741360a34168