{"id":"AZL-55796","summary":"CVE-2023-52582 affecting package kernel 5.15.200.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfs: Only call folio_start_fscache() one time for each folio\n\nIf a network filesystem using netfs implements a clamp_length()\nfunction, it can set subrequest lengths smaller than a page size.\n\nWhen we loop through the folios in netfs_rreq_unlock_folios() to\nset any folios to be written back, we need to make sure we only\ncall folio_start_fscache() once for each folio.\n\nOtherwise, this simple testcase:\n\n  mount -o fsc,rsize=1024,wsize=1024 127.0.0.1:/export /mnt/nfs\n  dd if=/dev/zero of=/mnt/nfs/file.bin bs=4096 count=1\n  1+0 records in\n  1+0 records out\n  4096 bytes (4.1 kB, 4.0 KiB) copied, 0.0126359 s, 324 kB/s\n  echo 3 \u003e /proc/sys/vm/drop_caches\n  cat /mnt/nfs/file.bin \u003e /dev/null\n\nwill trigger an oops similar to the following:\n\n  page dumped because: VM_BUG_ON_FOLIO(folio_test_private_2(folio))\n  ------------[ cut here ]------------\n  kernel BUG at include/linux/netfs.h:44!\n  ...\n  CPU: 5 PID: 134 Comm: kworker/u16:5 Kdump: loaded Not tainted 6.4.0-rc5\n  ...\n  RIP: 0010:netfs_rreq_unlock_folios+0x68e/0x730 [netfs]\n  ...\n  Call Trace:\n    netfs_rreq_assess+0x497/0x660 [netfs]\n    netfs_subreq_terminated+0x32b/0x610 [netfs]\n    nfs_netfs_read_completion+0x14e/0x1a0 [nfs]\n    nfs_read_completion+0x2f9/0x330 [nfs]\n    rpc_free_task+0x72/0xa0 [sunrpc]\n    rpc_async_release+0x46/0x70 [sunrpc]\n    process_one_work+0x3bd/0x710\n    worker_thread+0x89/0x610\n    kthread+0x181/0x1c0\n    ret_from_fork+0x29/0x50","modified":"2026-04-01T05:19:43.623902Z","published":"2024-03-02T22:15:49Z","upstream":["CVE-2023-52582"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-52582"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"5.15.200.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-55796.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}