4dbe38dc38
As Wen Xu reported in bugzilla, after image was injected with random data by fuzzing, inline inode would contain invalid reserved blkaddr, then during inline conversion, we will encounter illegal memory accessing reported by KASAN, the root cause of this is when writing out converted inline page, we will use invalid reserved blkaddr to update sit bitmap, result in accessing memory beyond sit bitmap boundary. In order to fix this issue, let's do sanity check with reserved block address of inline inode to avoid above condition. https://bugzilla.kernel.org/show_bug.cgi?id=200179 [ 1428.846352] BUG: KASAN: use-after-free in update_sit_entry+0x80/0x7f0 [ 1428.846618] Read of size 4 at addr ffff880194483540 by task a.out/2741 [ 1428.846855] CPU: 0 PID: 2741 Comm: a.out Tainted: G W 4.17.0+ #1 [ 1428.846858] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [ 1428.846860] Call Trace: [ 1428.846868] dump_stack+0x71/0xab [ 1428.846875] print_address_description+0x6b/0x290 [ 1428.846881] kasan_report+0x28e/0x390 [ 1428.846888] ? update_sit_entry+0x80/0x7f0 [ 1428.846898] update_sit_entry+0x80/0x7f0 [ 1428.846906] f2fs_allocate_data_block+0x6db/0xc70 [ 1428.846914] ? f2fs_get_node_info+0x14f/0x590 [ 1428.846920] do_write_page+0xc8/0x150 [ 1428.846928] f2fs_outplace_write_data+0xfe/0x210 [ 1428.846935] ? f2fs_do_write_node_page+0x170/0x170 [ 1428.846941] ? radix_tree_tag_clear+0xff/0x130 [ 1428.846946] ? __mod_node_page_state+0x22/0xa0 [ 1428.846951] ? inc_zone_page_state+0x54/0x100 [ 1428.846956] ? __test_set_page_writeback+0x336/0x5d0 [ 1428.846964] f2fs_convert_inline_page+0x407/0x6d0 [ 1428.846971] ? f2fs_read_inline_data+0x3b0/0x3b0 [ 1428.846978] ? __get_node_page+0x335/0x6b0 [ 1428.846987] f2fs_convert_inline_inode+0x41b/0x500 [ 1428.846994] ? f2fs_convert_inline_page+0x6d0/0x6d0 [ 1428.847000] ? kasan_unpoison_shadow+0x31/0x40 [ 1428.847005] ? kasan_kmalloc+0xa6/0xd0 [ 1428.847024] f2fs_file_mmap+0x79/0xc0 [ 1428.847029] mmap_region+0x58b/0x880 [ 1428.847037] ? arch_get_unmapped_area+0x370/0x370 [ 1428.847042] do_mmap+0x55b/0x7a0 [ 1428.847048] vm_mmap_pgoff+0x16f/0x1c0 [ 1428.847055] ? vma_is_stack_for_current+0x50/0x50 [ 1428.847062] ? __fsnotify_update_child_dentry_flags.part.1+0x160/0x160 [ 1428.847068] ? do_sys_open+0x206/0x2a0 [ 1428.847073] ? __fget+0xb4/0x100 [ 1428.847079] ksys_mmap_pgoff+0x278/0x360 [ 1428.847085] ? find_mergeable_anon_vma+0x50/0x50 [ 1428.847091] do_syscall_64+0x73/0x160 [ 1428.847098] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 1428.847102] RIP: 0033:0x7fb1430766ba [ 1428.847103] Code: 89 f5 41 54 49 89 fc 55 53 74 35 49 63 e8 48 63 da 4d 89 f9 49 89 e8 4d 63 d6 48 89 da 4c 89 ee 4c 89 e7 b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 56 5b 5d 41 5c 41 5d 41 5e 41 5f c3 0f 1f 00 [ 1428.847162] RSP: 002b:00007ffc651d9388 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 [ 1428.847167] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fb1430766ba [ 1428.847170] RDX: 0000000000000001 RSI: 0000000000001000 RDI: 0000000000000000 [ 1428.847173] RBP: 0000000000000003 R08: 0000000000000003 R09: 0000000000000000 [ 1428.847176] R10: 0000000000008002 R11: 0000000000000246 R12: 0000000000000000 [ 1428.847179] R13: 0000000000001000 R14: 0000000000008002 R15: 0000000000000000 [ 1428.847252] Allocated by task 2683: [ 1428.847372] kasan_kmalloc+0xa6/0xd0 [ 1428.847380] kmem_cache_alloc+0xc8/0x1e0 [ 1428.847385] getname_flags+0x73/0x2b0 [ 1428.847390] user_path_at_empty+0x1d/0x40 [ 1428.847395] vfs_statx+0xc1/0x150 [ 1428.847401] __do_sys_newlstat+0x7e/0xd0 [ 1428.847405] do_syscall_64+0x73/0x160 [ 1428.847411] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 1428.847466] Freed by task 2683: [ 1428.847566] __kasan_slab_free+0x137/0x190 [ 1428.847571] kmem_cache_free+0x85/0x1e0 [ 1428.847575] filename_lookup+0x191/0x280 [ 1428.847580] vfs_statx+0xc1/0x150 [ 1428.847585] __do_sys_newlstat+0x7e/0xd0 [ 1428.847590] do_syscall_64+0x73/0x160 [ 1428.847596] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 1428.847648] The buggy address belongs to the object at ffff880194483300 which belongs to the cache names_cache of size 4096 [ 1428.847946] The buggy address is located 576 bytes inside of 4096-byte region [ffff880194483300, ffff880194484300) [ 1428.848234] The buggy address belongs to the page: [ 1428.848366] page:ffffea0006512000 count:1 mapcount:0 mapping:ffff8801f3586380 index:0x0 compound_mapcount: 0 [ 1428.848606] flags: 0x17fff8000008100(slab|head) [ 1428.848737] raw: 017fff8000008100 dead000000000100 dead000000000200 ffff8801f3586380 [ 1428.848931] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 [ 1428.849122] page dumped because: kasan: bad access detected [ 1428.849305] Memory state around the buggy address: [ 1428.849436] ffff880194483400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 1428.849620] ffff880194483480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 1428.849804] >ffff880194483500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 1428.849985] ^ [ 1428.850120] ffff880194483580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 1428.850303] ffff880194483600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 1428.850498] ================================================================== Reported-by: Wen Xu <wen.xu@gatech.edu> Signed-off-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> |
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Documentation | ||
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arch | ||
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certs | ||
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include | ||
init | ||
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README |
README
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.