{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2023-53247",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2023-53247"
  ],
  "published": "2025-09-15T14:48:04Z",
  "summary": "btrfs: set_page_extent_mapped after read_folio in btrfs_cont_expand",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: set_page_extent_mapped after read_folio in btrfs_cont_expand\n\nWhile trying to get the subpage blocksize tests running, I hit the\nfollowing panic on generic/476\n\n  assertion failed: PagePrivate(page) && page->private, in fs/btrfs/subpage.c:229\n  kernel BUG at fs/btrfs/subpage.c:229!\n  Internal error: Oops - BUG: 00000000f2000800 [#1] SMP\n  CPU: 1 PID: 1453 Comm: fsstress Not tainted 6.4.0-rc7+ #12\n  Hardware name: QEMU KVM Virtual Machine, BIOS edk2-20230301gitf80f052277c8-26.fc38 03/01/2023\n  pstate: 61400005 (nZCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)\n  pc : btrfs_subpage_assert+0xbc/0xf0\n  lr : btrfs_subpage_assert+0xbc/0xf0\n  Call trace:\n   btrfs_subpage_assert+0xbc/0xf0\n   btrfs_subpage_clear_checked+0x38/0xc0\n   btrfs_page_clear_checked+0x48/0x98\n   btrfs_truncate_block+0x5d0/0x6a8\n   btrfs_cont_expand+0x5c/0x528\n   btrfs_write_check.isra.0+0xf8/0x150\n   btrfs_buffered_write+0xb4/0x760\n   btrfs_do_write_iter+0x2f8/0x4b0\n   btrfs_file_write_iter+0x1c/0x30\n   do_iter_readv_writev+0xc8/0x158\n   do_iter_write+0x9c/0x210\n   vfs_iter_write+0x24/0x40\n   iter_file_splice_write+0x224/0x390\n   direct_splice_actor+0x38/0x68\n   splice_direct_to_actor+0x12c/0x260\n   do_splice_direct+0x90/0xe8\n   generic_copy_file_range+0x50/0x90\n   vfs_copy_file_range+0x29c/0x470\n   __arm64_sys_copy_file_range+0xcc/0x498\n   invoke_syscall.constprop.0+0x80/0xd8\n   do_el0_svc+0x6c/0x168\n   el0_svc+0x50/0x1b0\n   el0t_64_sync_handler+0x114/0x120\n   el0t_64_sync+0x194/0x198\n\nThis happens because during btrfs_cont_expand we'll get a page, set it\nas mapped, and if it's not Uptodate we'll read it.  However between the\nread and re-locking the page we could have called release_folio() on the\npage, but left the page in the file mapping.  release_folio() can clear\nthe page private, and thus further down we blow up when we go to modify\nthe subpage bits.\n\nFix this by putting the set_page_extent_mapped() after the read.  This\nis safe because read_folio() will call set_page_extent_mapped() before\nit does the read, and then if we clear page private but leave it on the\nmapping we're completely safe re-setting set_page_extent_mapped().  With\nthis patch I can now run generic/476 without panicing.",
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.21-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v6",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v7",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v7l",
            "binary_version": "1:6.1.21-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi1-rpi-v8",
            "binary_version": "1:6.1.21-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.21-1+rpt1": {
            "linux_commit": "0afb5e98488aed7017b9bf321b575d0177feb7ed",
            "upstream_version": "6.1.21",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.42"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2023-53247"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0a5e0bc8e8618e32a6ca64450867628eb0a627bf"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a5880e69cf7fe4a0bb1eabae02205352d1b59b7b"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/17b17fcd6d446b95904a6929c40012ee7f0afc0c"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-05-12T04:54:46Z"
  }
}