{"id":"DEBIAN-CVE-2021-47623","details":"In the Linux kernel, the following vulnerability has been resolved:  powerpc/fixmap: Fix VM debug warning on unmap  Unmapping a fixmap entry is done by calling __set_fixmap() with FIXMAP_PAGE_CLEAR as flags.  Today, powerpc __set_fixmap() calls map_kernel_page().  map_kernel_page() is not happy when called a second time for the same page.  \tWARNING: CPU: 0 PID: 1 at arch/powerpc/mm/pgtable.c:194 set_pte_at+0xc/0x1e8 \tCPU: 0 PID: 1 Comm: swapper Not tainted 5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty #682 \tNIP:  c0017cd4 LR: c00187f0 CTR: 00000010 \tREGS: e1011d50 TRAP: 0700   Not tainted  (5.16.0-rc3-s3k-dev-01993-g350ff07feb7d-dirty) \tMSR:  00029032 \u003cEE,ME,IR,DR,RI\u003e  CR: 42000208  XER: 00000000  \tGPR00: c0165fec e1011e10 c14c0000 c0ee2550 ff800000 c0f3d000 00000000 c001686c \tGPR08: 00001000 b00045a9 00000001 c0f58460 c0f50000 00000000 c0007e10 00000000 \tGPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 \tGPR24: 00000000 00000000 c0ee2550 00000000 c0f57000 00000ff8 00000000 ff800000 \tNIP [c0017cd4] set_pte_at+0xc/0x1e8 \tLR [c00187f0] map_kernel_page+0x9c/0x100 \tCall Trace: \t[e1011e10] [c0736c68] vsnprintf+0x358/0x6c8 (unreliable) \t[e1011e30] [c0165fec] __set_fixmap+0x30/0x44 \t[e1011e40] [c0c13bdc] early_iounmap+0x11c/0x170 \t[e1011e70] [c0c06cb0] ioremap_legacy_serial_console+0x88/0xc0 \t[e1011e90] [c0c03634] do_one_initcall+0x80/0x178 \t[e1011ef0] [c0c0385c] kernel_init_freeable+0xb4/0x250 \t[e1011f20] [c0007e34] kernel_init+0x24/0x140 \t[e1011f30] [c0016268] ret_from_kernel_thread+0x5c/0x64 \tInstruction dump: \t7fe3fb78 48019689 80010014 7c630034 83e1000c 5463d97e 7c0803a6 38210010 \t4e800020 81250000 712a0001 41820008 \u003c0fe00000\u003e 9421ffe0 93e1001c 48000030  Implement unmap_kernel_page() which clears an existing pte.","modified":"2026-09-15T09:02:36.137724528Z","published":"2024-07-16T12:15:02.483Z","upstream":["CVE-2021-47623"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2021-47623"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.16.10-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47623.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.16.10-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47623.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.16.10-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2021-47623.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}