{"id":"CVE-2021-47497","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnvmem: Fix shift-out-of-bound (UBSAN) with byte size cells\n\nIf a cell has 'nbits' equal to a multiple of BITS_PER_BYTE the logic\n\n *p &= GENMASK((cell-\u003enbits%BITS_PER_BYTE) - 1, 0);\n\nwill become undefined behavior because nbits modulo BITS_PER_BYTE is 0, and we\nsubtract one from that making a large number that is then shifted more than the\nnumber of bits that fit into an unsigned long.\n\nUBSAN reports this problem:\n\n UBSAN: shift-out-of-bounds in drivers/nvmem/core.c:1386:8\n shift exponent 64 is too large for 64-bit type 'unsigned long'\n CPU: 6 PID: 7 Comm: kworker/u16:0 Not tainted 5.15.0-rc3+ #9\n Hardware name: Google Lazor (rev3+) with KB Backlight (DT)\n Workqueue: events_unbound deferred_probe_work_func\n Call trace:\n  dump_backtrace+0x0/0x170\n  show_stack+0x24/0x30\n  dump_stack_lvl+0x64/0x7c\n  dump_stack+0x18/0x38\n  ubsan_epilogue+0x10/0x54\n  __ubsan_handle_shift_out_of_bounds+0x180/0x194\n  __nvmem_cell_read+0x1ec/0x21c\n  nvmem_cell_read+0x58/0x94\n  nvmem_cell_read_variable_common+0x4c/0xb0\n  nvmem_cell_read_variable_le_u32+0x40/0x100\n  a6xx_gpu_init+0x170/0x2f4\n  adreno_bind+0x174/0x284\n  component_bind_all+0xf0/0x264\n  msm_drm_bind+0x1d8/0x7a0\n  try_to_bring_up_master+0x164/0x1ac\n  __component_add+0xbc/0x13c\n  component_add+0x20/0x2c\n  dp_display_probe+0x340/0x384\n  platform_probe+0xc0/0x100\n  really_probe+0x110/0x304\n  __driver_probe_device+0xb8/0x120\n  driver_probe_device+0x4c/0xfc\n  __device_attach_driver+0xb0/0x128\n  bus_for_each_drv+0x90/0xdc\n  __device_attach+0xc8/0x174\n  device_initial_probe+0x20/0x2c\n  bus_probe_device+0x40/0xa4\n  deferred_probe_work_func+0x7c/0xb8\n  process_one_work+0x128/0x21c\n  process_scheduled_works+0x40/0x54\n  worker_thread+0x1ec/0x2a8\n  kthread+0x138/0x158\n  ret_from_fork+0x10/0x20\n\nFix it by making sure there are any bits to mask out.","modified":"2026-03-15T22:43:14.874365Z","published":"2024-05-22T09:15:11.513Z","related":["ALSA-2024:7000","ALSA-2024:7001","SUSE-SU-2024:1979-1","SUSE-SU-2024:1983-1","SUSE-SU-2024:2008-1","SUSE-SU-2024:2010-1","SUSE-SU-2024:2011-1","SUSE-SU-2024:2019-1","SUSE-SU-2024:2183-1","SUSE-SU-2024:2184-1","SUSE-SU-2024:2185-1","SUSE-SU-2024:2189-1","SUSE-SU-2024:2190-1"],"references":[{"type":"FIX","url":"https://git.kernel.org/stable/c/60df06bbdf497e37ed25ad40572c362e5b0998df"},{"type":"FIX","url":"https://git.kernel.org/stable/c/abcb8d33e4d2215ccde5ab5ccf9f730a59d79d97"},{"type":"FIX","url":"https://git.kernel.org/stable/c/eb0fc8e7170e61eaf65d28dee4a8baf4e86b19ca"},{"type":"FIX","url":"https://git.kernel.org/stable/c/0594f1d048d8dc338eb9a240021b1d00ae1eb082"},{"type":"FIX","url":"https://git.kernel.org/stable/c/0e822e5413da1af28cca350cb1cb42b6133bdcae"},{"type":"FIX","url":"https://git.kernel.org/stable/c/2df6c023050205c4d04ffc121bc549f65cb8d1df"},{"type":"FIX","url":"https://git.kernel.org/stable/c/57e48886401b14cd351423fabfec2cfd18df4f66"},{"type":"FIX","url":"https://git.kernel.org/stable/c/5d388fa01fa6eb310ac023a363a6cb216d9d8fe9"}],"affected":[{"database_specific":{"unresolved_ranges":[{"events":[{"introduced":"4.3"},{"fixed":"4.4.290"}]},{"events":[{"introduced":"4.5"},{"fixed":"4.9.288"}]},{"events":[{"introduced":"4.10"},{"fixed":"4.14.252"}]},{"events":[{"introduced":"4.15"},{"fixed":"4.19.213"}]},{"events":[{"introduced":"4.20"},{"fixed":"5.4.155"}]},{"events":[{"introduced":"5.5"},{"fixed":"5.10.75"}]},{"events":[{"introduced":"5.11"},{"fixed":"5.14.14"}]},{"events":[{"introduced":"0"},{"last_affected":"5.15-rc1"}]},{"events":[{"introduced":"0"},{"last_affected":"5.15-rc2"}]},{"events":[{"introduced":"0"},{"last_affected":"5.15-rc3"}]},{"events":[{"introduced":"0"},{"last_affected":"5.15-rc4"}]},{"events":[{"introduced":"0"},{"last_affected":"5.15-rc5"}]}],"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47497.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:H/I:H/A:H"}]}