CVE-2024-44942: f2fs: fix to do sanity check on F2FS_INLINE_DATA flag in inode during GC

In the Linux kernel, the following vulnerability has been resolved:

f2fs: fix to do sanity check on F2FSINLINEDATA flag in inode during GC

syzbot reports a f2fs bug as below:

------------[ cut here ]------------ kernel BUG at fs/f2fs/inline.c:258! CPU: 1 PID: 34 Comm: kworker/u8:2 Not tainted 6.9.0-rc6-syzkaller-00012-g9e4bc4bcae01 #0 RIP: 0010:f2fswriteinlinedata+0x781/0x790 fs/f2fs/inline.c:258 Call Trace: f2fswritesingledatapage+0xb65/0x1d60 fs/f2fs/data.c:2834 f2fswritecachepages fs/f2fs/data.c:3133 [inline] f2fswritedatapages fs/f2fs/data.c:3288 [inline] f2fswritedatapages+0x1efe/0x3a90 fs/f2fs/data.c:3315 dowritepages+0x35b/0x870 mm/page-writeback.c:2612 writebacksingleinode+0x165/0x10b0 fs/fs-writeback.c:1650 writebacksbinodes+0x905/0x1260 fs/fs-writeback.c:1941 wbwriteback+0x457/0xce0 fs/fs-writeback.c:2117 wbdowriteback fs/fs-writeback.c:2264 [inline] wbworkfn+0x410/0x1090 fs/fs-writeback.c:2304 processonework kernel/workqueue.c:3254 [inline] processscheduledworks+0xa12/0x17c0 kernel/workqueue.c:3335 workerthread+0x86d/0xd70 kernel/workqueue.c:3416 kthread+0x2f2/0x390 kernel/kthread.c:388 retfromfork+0x4d/0x80 arch/x86/kernel/process.c:147 retfromforkasm+0x1a/0x30 arch/x86/entry/entry64.S:244

The root cause is: inlinedata inode can be fuzzed, so that there may be valid blkaddr in its direct node, once f2fs triggers background GC to migrate the block, it will hit f2fsbugon() during dirty page writeback.

Let's add sanity check on F2FSINLINEDATA flag in inode during GC, so that, it can forbid migrating inlinedata inode's data block for fixing.