CVE-2022-50782

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> ext4: fix bug_on in __es_tree_search caused by bad quota inode<br /> <br /> We got a issue as fllows:<br /> ==================================================================<br /> kernel BUG at fs/ext4/extents_status.c:202!<br /> invalid opcode: 0000 [#1] PREEMPT SMP<br /> CPU: 1 PID: 810 Comm: mount Not tainted 6.1.0-rc1-next-g9631525255e3 #352<br /> RIP: 0010:__es_tree_search.isra.0+0xb8/0xe0<br /> RSP: 0018:ffffc90001227900 EFLAGS: 00010202<br /> RAX: 0000000000000000 RBX: 0000000077512a0f RCX: 0000000000000000<br /> RDX: 0000000000000002 RSI: 0000000000002a10 RDI: ffff8881004cd0c8<br /> RBP: ffff888177512ac8 R08: 47ffffffffffffff R09: 0000000000000001<br /> R10: 0000000000000001 R11: 00000000000679af R12: 0000000000002a10<br /> R13: ffff888177512d88 R14: 0000000077512a10 R15: 0000000000000000<br /> FS: 00007f4bd76dbc40(0000)GS:ffff88842fd00000(0000)knlGS:0000000000000000<br /> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033<br /> CR2: 00005653bf993cf8 CR3: 000000017bfdf000 CR4: 00000000000006e0<br /> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000<br /> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400<br /> Call Trace:<br /> <br /> ext4_es_cache_extent+0xe2/0x210<br /> ext4_cache_extents+0xd2/0x110<br /> ext4_find_extent+0x5d5/0x8c0<br /> ext4_ext_map_blocks+0x9c/0x1d30<br /> ext4_map_blocks+0x431/0xa50<br /> ext4_getblk+0x82/0x340<br /> ext4_bread+0x14/0x110<br /> ext4_quota_read+0xf0/0x180<br /> v2_read_header+0x24/0x90<br /> v2_check_quota_file+0x2f/0xa0<br /> dquot_load_quota_sb+0x26c/0x760<br /> dquot_load_quota_inode+0xa5/0x190<br /> ext4_enable_quotas+0x14c/0x300<br /> __ext4_fill_super+0x31cc/0x32c0<br /> ext4_fill_super+0x115/0x2d0<br /> get_tree_bdev+0x1d2/0x360<br /> ext4_get_tree+0x19/0x30<br /> vfs_get_tree+0x26/0xe0<br /> path_mount+0x81d/0xfc0<br /> do_mount+0x8d/0xc0<br /> __x64_sys_mount+0xc0/0x160<br /> do_syscall_64+0x35/0x80<br /> entry_SYSCALL_64_after_hwframe+0x63/0xcd<br /> <br /> ==================================================================<br /> <br /> Above issue may happen as follows:<br /> -------------------------------------<br /> ext4_fill_super<br /> ext4_orphan_cleanup<br /> ext4_enable_quotas<br /> ext4_quota_enable<br /> ext4_iget --&gt; get error inode <br /> ext4_ext_check_inode --&gt; Wrong imode makes it escape inspection<br /> make_bad_inode(inode) --&gt; EXT4_BOOT_LOADER_INO set imode<br /> dquot_load_quota_inode<br /> vfs_setup_quota_inode --&gt; check pass<br /> dquot_load_quota_sb<br /> v2_check_quota_file<br /> v2_read_header<br /> ext4_quota_read<br /> ext4_bread<br /> ext4_getblk<br /> ext4_map_blocks<br /> ext4_ext_map_blocks<br /> ext4_find_extent<br /> ext4_cache_extents<br /> ext4_es_cache_extent<br /> __es_tree_search.isra.0<br /> ext4_es_end --&gt; Wrong extents trigger BUG_ON<br /> <br /> In the above issue, s_usr_quota_inum is set to 5, but inode contains<br /> incorrect imode and disordered extents. Because 5 is EXT4_BOOT_LOADER_INO,<br /> the ext4_ext_check_inode check in the ext4_iget function can be bypassed,<br /> finally, the extents that are not checked trigger the BUG_ON in the<br /> __es_tree_search function. To solve this issue, check whether the inode is<br /> bad_inode in vfs_setup_quota_inode().