ghsa-rr6m-3x7m-qjff
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix races between hole punching and AIO+DIO
After commit "ocfs2: return real error code in ocfs2_dio_wr_get_block", fstests/generic/300 become from always failed to sometimes failed:
======================================================================== [ 473.293420 ] run fstests generic/300
[ 475.296983 ] JBD2: Ignoring recovery information on journal [ 475.302473 ] ocfs2: Mounting device (253,1) on (node local, slot 0) with ordered data mode. [ 494.290998 ] OCFS2: ERROR (device dm-1): ocfs2_change_extent_flag: Owner 5668 has an extent at cpos 78723 which can no longer be found [ 494.291609 ] On-disk corruption discovered. Please run fsck.ocfs2 once the filesystem is unmounted. [ 494.292018 ] OCFS2: File system is now read-only. [ 494.292224 ] (kworker/19:11,2628,19):ocfs2_mark_extent_written:5272 ERROR: status = -30 [ 494.292602 ] (kworker/19:11,2628,19):ocfs2_dio_end_io_write:2374 ERROR: status = -3 fio: io_u error on file /mnt/scratch/racer: Read-only file system: write offset=460849152, buflen=131072 =========================================================================
In __blockdev_direct_IO, ocfs2_dio_wr_get_block is called to add unwritten extents to a list. extents are also inserted into extent tree in ocfs2_write_begin_nolock. Then another thread call fallocate to puch a hole at one of the unwritten extent. The extent at cpos was removed by ocfs2_remove_extent(). At end io worker thread, ocfs2_search_extent_list found there is no such extent at the cpos.
T1 T2 T3
inode lock
...
insert extents
...
inode unlock
ocfs2_fallocate __ocfs2_change_file_space inode lock lock ip_alloc_sem ocfs2_remove_inode_range inode ocfs2_remove_btree_range ocfs2_remove_extent ^---remove the extent at cpos 78723 ... unlock ip_alloc_sem inode unlock ocfs2_dio_end_io ocfs2_dio_end_io_write lock ip_alloc_sem ocfs2_mark_extent_written ocfs2_change_extent_flag ocfs2_search_extent_list ^---failed to find extent ... unlock ip_alloc_sem
In most filesystems, fallocate is not compatible with racing with AIO+DIO, so fix it by adding to wait for all dio before fallocate/punch_hole like ext4.
{
"affected": [],
"aliases": [
"CVE-2024-40943"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-07-12T13:15:16Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix races between hole punching and AIO+DIO\n\nAfter commit \"ocfs2: return real error code in ocfs2_dio_wr_get_block\",\nfstests/generic/300 become from always failed to sometimes failed:\n\n========================================================================\n[ 473.293420 ] run fstests generic/300\n\n[ 475.296983 ] JBD2: Ignoring recovery information on journal\n[ 475.302473 ] ocfs2: Mounting device (253,1) on (node local, slot 0) with ordered data mode.\n[ 494.290998 ] OCFS2: ERROR (device dm-1): ocfs2_change_extent_flag: Owner 5668 has an extent at cpos 78723 which can no longer be found\n[ 494.291609 ] On-disk corruption discovered. Please run fsck.ocfs2 once the filesystem is unmounted.\n[ 494.292018 ] OCFS2: File system is now read-only.\n[ 494.292224 ] (kworker/19:11,2628,19):ocfs2_mark_extent_written:5272 ERROR: status = -30\n[ 494.292602 ] (kworker/19:11,2628,19):ocfs2_dio_end_io_write:2374 ERROR: status = -3\nfio: io_u error on file /mnt/scratch/racer: Read-only file system: write offset=460849152, buflen=131072\n=========================================================================\n\nIn __blockdev_direct_IO, ocfs2_dio_wr_get_block is called to add unwritten\nextents to a list. extents are also inserted into extent tree in\nocfs2_write_begin_nolock. Then another thread call fallocate to puch a\nhole at one of the unwritten extent. The extent at cpos was removed by\nocfs2_remove_extent(). At end io worker thread, ocfs2_search_extent_list\nfound there is no such extent at the cpos.\n\n T1 T2 T3\n inode lock\n ...\n insert extents\n ...\n inode unlock\nocfs2_fallocate\n __ocfs2_change_file_space\n inode lock\n lock ip_alloc_sem\n ocfs2_remove_inode_range inode\n ocfs2_remove_btree_range\n ocfs2_remove_extent\n ^---remove the extent at cpos 78723\n ...\n unlock ip_alloc_sem\n inode unlock\n ocfs2_dio_end_io\n ocfs2_dio_end_io_write\n lock ip_alloc_sem\n ocfs2_mark_extent_written\n ocfs2_change_extent_flag\n ocfs2_search_extent_list\n ^---failed to find extent\n ...\n unlock ip_alloc_sem\n\nIn most filesystems, fallocate is not compatible with racing with AIO+DIO,\nso fix it by adding to wait for all dio before fallocate/punch_hole like\next4.",
"id": "GHSA-rr6m-3x7m-qjff",
"modified": "2024-07-12T15:31:28Z",
"published": "2024-07-12T15:31:28Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-40943"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/050ce8af6838c71e872e982b50d3f1bec21da40e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/117b9c009b72a6c2ebfd23484354dfee2d9570d2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/38825ff9da91d2854dcf6d9ac320a7e641e10f25"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3c26b5d21b1239e9c7fd31ba7d9b2d7bdbaa68d9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3c361f313d696df72f9bccf058510e9ec737b9b1"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/952b023f06a24b2ad6ba67304c4c84d45bea2f18"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e8e2db1adac47970a6a9225f3858e9aa0e86287f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ea042dc2bea19d72e37c298bf65a9c341ef3fff3"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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