ocfs2: validate inline xattrs during inode block validation

Summary

In the Linux kernel, the following vulnerability has been resolved: ocfs2: validate inline xattrs during inode block validation Patch series "ocfs2: validate xattr entry bounds", v7. This series validates OCFS2 xattr entry name/value bounds when xattr metadata is read and validated, before getxattr() or listxattr() can walk out-of-range entry arrays or offsets from corrupted metadata. This patch (of 2): ocfs2_validate_inode_block() verifies a dinode before OCFS2 users walk metadata from it, but inline xattr metadata is still checked only in operation-specific consumers. The existing ibody lookup helper validates inline header placement and entry count, but inode block validation does not reject entry name/value bounds. Add a flat xattr entry validator and call it from inode block validation for inline xattrs. Keep the operation paths on their existing header/count lookup checks; the full entry bounds check now runs when the inode block is validated at read time. Reject corrupted inline xattr metadata before ocfs2_xattr_ibody_get() or listxattr() can walk past the inline storage. Validation reproduced this kernel report: BUG: KASAN: use-after-free in ocfs2_xattr_find_entry+0x5a/0x170 Read of size 2 at addr ffff8881242a2000 by task python3/529 Call Trace: dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 kasan_report+0xe0/0x110 ocfs2_xattr_find_entry+0x5a/0x170 ocfs2_xattr_get_nolock+0x20a/0x820 ocfs2_xattr_get+0x10c/0x1e0 __vfs_getxattr+0xe2/0x130 vfs_getxattr+0x185/0x1b0