FKIE_CVE-2022-50638

Vulnerability from fkie_nvd - Published: 2025-12-09 01:16 - Updated: 2025-12-09 18:37
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: ext4: fix bug_on in __es_tree_search caused by bad boot loader inode We got a issue as fllows: ================================================================== kernel BUG at fs/ext4/extents_status.c:203! invalid opcode: 0000 [#1] PREEMPT SMP CPU: 1 PID: 945 Comm: cat Not tainted 6.0.0-next-20221007-dirty #349 RIP: 0010:ext4_es_end.isra.0+0x34/0x42 RSP: 0018:ffffc9000143b768 EFLAGS: 00010203 RAX: 0000000000000000 RBX: ffff8881769cd0b8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8fc27cf7 RDI: 00000000ffffffff RBP: ffff8881769cd0bc R08: 0000000000000000 R09: ffffc9000143b5f8 R10: 0000000000000001 R11: 0000000000000001 R12: ffff8881769cd0a0 R13: ffff8881768e5668 R14: 00000000768e52f0 R15: 0000000000000000 FS: 00007f359f7f05c0(0000)GS:ffff88842fd00000(0000)knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f359f5a2000 CR3: 000000017130c000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __es_tree_search.isra.0+0x6d/0xf5 ext4_es_cache_extent+0xfa/0x230 ext4_cache_extents+0xd2/0x110 ext4_find_extent+0x5d5/0x8c0 ext4_ext_map_blocks+0x9c/0x1d30 ext4_map_blocks+0x431/0xa50 ext4_mpage_readpages+0x48e/0xe40 ext4_readahead+0x47/0x50 read_pages+0x82/0x530 page_cache_ra_unbounded+0x199/0x2a0 do_page_cache_ra+0x47/0x70 page_cache_ra_order+0x242/0x400 ondemand_readahead+0x1e8/0x4b0 page_cache_sync_ra+0xf4/0x110 filemap_get_pages+0x131/0xb20 filemap_read+0xda/0x4b0 generic_file_read_iter+0x13a/0x250 ext4_file_read_iter+0x59/0x1d0 vfs_read+0x28f/0x460 ksys_read+0x73/0x160 __x64_sys_read+0x1e/0x30 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd </TASK> ================================================================== In the above issue, ioctl invokes the swap_inode_boot_loader function to swap inode<5> and inode<12>. However, inode<5> contain incorrect imode and disordered extents, and i_nlink is set to 1. The extents check for inode in the ext4_iget function can be bypassed bacause 5 is EXT4_BOOT_LOADER_INO. While links_count is set to 1, the extents are not initialized in swap_inode_boot_loader. After the ioctl command is executed successfully, the extents are swapped to inode<12>, in this case, run the `cat` command to view inode<12>. And Bug_ON is triggered due to the incorrect extents. When the boot loader inode is not initialized, its imode can be one of the following: 1) the imode is a bad type, which is marked as bad_inode in ext4_iget and set to S_IFREG. 2) the imode is good type but not S_IFREG. 3) the imode is S_IFREG. The BUG_ON may be triggered by bypassing the check in cases 1 and 2. Therefore, when the boot loader inode is bad_inode or its imode is not S_IFREG, initialize the inode to avoid triggering the BUG.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5f8d36abd2059bf1bd016b17d1fe78d8613deddd
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/71e99ec1315fe98d322b17b9a28f204aaf15ffee
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/78e335fb573e6a85718c4c24d5a052718a99a9ed
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/991ed014de0840c5dc405b679168924afb2952ac
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a125c8806b7d3c3815b6f9f59d395b9d7527b0ef
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a95ba369255ddcdc5e43d38bc5203537bdf3a518
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d480a49c15c465cb9a16db1379f4996e9b5bb9cc
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e76ede9d2c9e0af4573342b56d7cdbf757c18084
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/feec0ea94c5ef4aa118750284c8a921698733ef2
Impacted products
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix bug_on in __es_tree_search caused by bad boot loader inode\n\nWe got a issue as fllows:\n==================================================================\n kernel BUG at fs/ext4/extents_status.c:203!\n invalid opcode: 0000 [#1] PREEMPT SMP\n CPU: 1 PID: 945 Comm: cat Not tainted 6.0.0-next-20221007-dirty #349\n RIP: 0010:ext4_es_end.isra.0+0x34/0x42\n RSP: 0018:ffffc9000143b768 EFLAGS: 00010203\n RAX: 0000000000000000 RBX: ffff8881769cd0b8 RCX: 0000000000000000\n RDX: 0000000000000000 RSI: ffffffff8fc27cf7 RDI: 00000000ffffffff\n RBP: ffff8881769cd0bc R08: 0000000000000000 R09: ffffc9000143b5f8\n R10: 0000000000000001 R11: 0000000000000001 R12: ffff8881769cd0a0\n R13: ffff8881768e5668 R14: 00000000768e52f0 R15: 0000000000000000\n FS: 00007f359f7f05c0(0000)GS:ffff88842fd00000(0000)knlGS:0000000000000000\n CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007f359f5a2000 CR3: 000000017130c000 CR4: 00000000000006e0\n DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\n DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\n Call Trace:\n  \u003cTASK\u003e\n  __es_tree_search.isra.0+0x6d/0xf5\n  ext4_es_cache_extent+0xfa/0x230\n  ext4_cache_extents+0xd2/0x110\n  ext4_find_extent+0x5d5/0x8c0\n  ext4_ext_map_blocks+0x9c/0x1d30\n  ext4_map_blocks+0x431/0xa50\n  ext4_mpage_readpages+0x48e/0xe40\n  ext4_readahead+0x47/0x50\n  read_pages+0x82/0x530\n  page_cache_ra_unbounded+0x199/0x2a0\n  do_page_cache_ra+0x47/0x70\n  page_cache_ra_order+0x242/0x400\n  ondemand_readahead+0x1e8/0x4b0\n  page_cache_sync_ra+0xf4/0x110\n  filemap_get_pages+0x131/0xb20\n  filemap_read+0xda/0x4b0\n  generic_file_read_iter+0x13a/0x250\n  ext4_file_read_iter+0x59/0x1d0\n  vfs_read+0x28f/0x460\n  ksys_read+0x73/0x160\n  __x64_sys_read+0x1e/0x30\n  do_syscall_64+0x35/0x80\n  entry_SYSCALL_64_after_hwframe+0x63/0xcd\n  \u003c/TASK\u003e\n==================================================================\n\nIn the above issue, ioctl invokes the swap_inode_boot_loader function to\nswap inode\u003c5\u003e and inode\u003c12\u003e. However, inode\u003c5\u003e contain incorrect imode and\ndisordered extents, and i_nlink is set to 1. The extents check for inode in\nthe ext4_iget function can be bypassed bacause 5 is EXT4_BOOT_LOADER_INO.\nWhile links_count is set to 1, the extents are not initialized in\nswap_inode_boot_loader. After the ioctl command is executed successfully,\nthe extents are swapped to inode\u003c12\u003e, in this case, run the `cat` command\nto view inode\u003c12\u003e. And Bug_ON is triggered due to the incorrect extents.\n\nWhen the boot loader inode is not initialized, its imode can be one of the\nfollowing:\n1) the imode is a bad type, which is marked as bad_inode in ext4_iget and\n   set to S_IFREG.\n2) the imode is good type but not S_IFREG.\n3) the imode is S_IFREG.\n\nThe BUG_ON may be triggered by bypassing the check in cases 1 and 2.\nTherefore, when the boot loader inode is bad_inode or its imode is not\nS_IFREG, initialize the inode to avoid triggering the BUG."
    }
  ],
  "id": "CVE-2022-50638",
  "lastModified": "2025-12-09T18:37:13.640",
  "metrics": {},
  "published": "2025-12-09T01:16:46.120",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5f8d36abd2059bf1bd016b17d1fe78d8613deddd"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/71e99ec1315fe98d322b17b9a28f204aaf15ffee"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/78e335fb573e6a85718c4c24d5a052718a99a9ed"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/991ed014de0840c5dc405b679168924afb2952ac"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a125c8806b7d3c3815b6f9f59d395b9d7527b0ef"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a95ba369255ddcdc5e43d38bc5203537bdf3a518"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d480a49c15c465cb9a16db1379f4996e9b5bb9cc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e76ede9d2c9e0af4573342b56d7cdbf757c18084"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/feec0ea94c5ef4aa118750284c8a921698733ef2"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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