In the Linux kernel, the following vulnerability has been resolved:
f2fs: assign CURSEG_ALL_DATA_ATGC if blkaddr is valid
mkdir /mnt/test/comp f2fs_io setflags compression /mnt/test/comp dd if=/dev/zero of=/mnt/test/comp/testfile bs=16k count=1 truncate --size 13 /mnt/test/comp/testfile
In the above scenario, we can get a BUG_ON. kernel BUG at fs/f2fs/segment.c:3589! Call Trace: do_write_page+0x78/0x390 [f2fs] f2fs_outplace_write_data+0x62/0xb0 [f2fs] f2fs_do_write_data_page+0x275/0x740 [f2fs] f2fs_write_single_data_page+0x1dc/0x8f0 [f2fs] f2fs_write_multi_pages+0x1e5/0xae0 [f2fs] f2fs_write_cache_pages+0xab1/0xc60 [f2fs] f2fs_write_data_pages+0x2d8/0x330 [f2fs] do_writepages+0xcf/0x270 __writeback_single_inode+0x44/0x350 writeback_sb_inodes+0x242/0x530 __writeback_inodes_wb+0x54/0xf0 wb_writeback+0x192/0x310 wb_workfn+0x30d/0x400
The reason is we gave CURSEG_ALL_DATA_ATGC to COMPR_ADDR where the page was set the gcing flag by set_cluster_dirty().