f2fs: let's avoid panic if extent_tree is not created

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: f2fs: let's avoid panic if extent_tree is not created This patch avoids the below panic. pc : __lookup_extent_tree+0xd8/0x760 lr : f2fs_do_write_data_page+0x104/0x87c sp : ffffffc010cbb3c0 x29: ffffffc010cbb3e0 x28: 0000000000000000 x27: ffffff8803e7f020 x26: ffffff8803e7ed40 x25: ffffff8803e7f020 x24: ffffffc010cbb460 x23: ffffffc010cbb480 x22: 0000000000000000 x21: 0000000000000000 x20: ffffffff22e90900 x19: 0000000000000000 x18: ffffffc010c5d080 x17: 0000000000000000 x16: 0000000000000020 x15: ffffffdb1acdbb88 x14: ffffff888759e2b0 x13: 0000000000000000 x12: ffffff802da49000 x11: 000000000a001200 x10: ffffff8803e7ed40 x9 : ffffff8023195800 x8 : ffffff802da49078 x7 : 0000000000000001 x6 : 0000000000000000 x5 : 0000000000000006 x4 : ffffffc010cbba28 x3 : 0000000000000000 x2 : ffffffc010cbb480 x1 : 0000000000000000 x0 : ffffff8803e7ed40 Call trace: __lookup_extent_tree+0xd8/0x760 f2fs_do_write_data_page+0x104/0x87c f2fs_write_single_data_page+0x420/0xb60 f2fs_write_cache_pages+0x418/0xb1c __f2fs_write_data_pages+0x428/0x58c f2fs_write_data_pages+0x30/0x40 do_writepages+0x88/0x190 __writeback_single_inode+0x48/0x448 writeback_sb_inodes+0x468/0x9e8 __writeback_inodes_wb+0xb8/0x2a4 wb_writeback+0x33c/0x740 wb_do_writeback+0x2b4/0x400 wb_workfn+0xe4/0x34c process_one_work+0x24c/0x5bc worker_thread+0x3e8/0xa50 kthread+0x150/0x1b4

References

• https://git.kernel.org/stable/c/dd83a9763e29ed7a21c8a43f7a62cd0a6bf74692
• https://git.kernel.org/stable/c/ff85a1dbd90d29f73033177ff8d8de4a27d9721c
• https://git.kernel.org/stable/c/557e85ff9afef6d45020b6f09357111d38033c31
• https://git.kernel.org/stable/c/72009139a661ade5cb1da4239734ed02fa1cfff0
• https://git.kernel.org/stable/c/2c129e868992621a739bdd57a5bffa3985ef1b91
• https://git.kernel.org/stable/c/1c38cdc747f00daf7394535eae5afc4c503c59bb
• https://git.kernel.org/stable/c/df9d44b645b83fffccfb4e28c1f93376585fdec8