{"id":"CVE-2021-47441","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmlxsw: thermal: Fix out-of-bounds memory accesses\n\nCurrently, mlxsw allows cooling states to be set above the maximum\ncooling state supported by the driver:\n\n # cat /sys/class/thermal/thermal_zone2/cdev0/type\n mlxsw_fan\n # cat /sys/class/thermal/thermal_zone2/cdev0/max_state\n 10\n # echo 18 \u003e /sys/class/thermal/thermal_zone2/cdev0/cur_state\n # echo $?\n 0\n\nThis results in out-of-bounds memory accesses when thermal state\ntransition statistics are enabled (CONFIG_THERMAL_STATISTICS=y), as the\ntransition table is accessed with a too large index (state) [1].\n\nAccording to the thermal maintainer, it is the responsibility of the\ndriver to reject such operations [2].\n\nTherefore, return an error when the state to be set exceeds the maximum\ncooling state supported by the driver.\n\nTo avoid dead code, as suggested by the thermal maintainer [3],\npartially revert commit a421ce088ac8 (\"mlxsw: core: Extend cooling\ndevice with cooling levels\") that tried to interpret these invalid\ncooling states (above the maximum) in a special way. The cooling levels\narray is not removed in order to prevent the fans going below 20% PWM,\nwhich would cause them to get stuck at 0% PWM.\n\n[1]\nBUG: KASAN: slab-out-of-bounds in thermal_cooling_device_stats_update+0x271/0x290\nRead of size 4 at addr ffff8881052f7bf8 by task kworker/0:0/5\n\nCPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.15.0-rc3-custom-45935-gce1adf704b14 #122\nHardware name: Mellanox Technologies Ltd. \"MSN2410-CB2FO\"/\"SA000874\", BIOS 4.6.5 03/08/2016\nWorkqueue: events_freezable_power_ thermal_zone_device_check\nCall Trace:\n dump_stack_lvl+0x8b/0xb3\n print_address_description.constprop.0+0x1f/0x140\n kasan_report.cold+0x7f/0x11b\n thermal_cooling_device_stats_update+0x271/0x290\n __thermal_cdev_update+0x15e/0x4e0\n thermal_cdev_update+0x9f/0xe0\n step_wise_throttle+0x770/0xee0\n thermal_zone_device_update+0x3f6/0xdf0\n process_one_work+0xa42/0x1770\n worker_thread+0x62f/0x13e0\n kthread+0x3ee/0x4e0\n ret_from_fork+0x1f/0x30\n\nAllocated by task 1:\n kasan_save_stack+0x1b/0x40\n __kasan_kmalloc+0x7c/0x90\n thermal_cooling_device_setup_sysfs+0x153/0x2c0\n __thermal_cooling_device_register.part.0+0x25b/0x9c0\n thermal_cooling_device_register+0xb3/0x100\n mlxsw_thermal_init+0x5c5/0x7e0\n __mlxsw_core_bus_device_register+0xcb3/0x19c0\n mlxsw_core_bus_device_register+0x56/0xb0\n mlxsw_pci_probe+0x54f/0x710\n local_pci_probe+0xc6/0x170\n pci_device_probe+0x2b2/0x4d0\n really_probe+0x293/0xd10\n __driver_probe_device+0x2af/0x440\n driver_probe_device+0x51/0x1e0\n __driver_attach+0x21b/0x530\n bus_for_each_dev+0x14c/0x1d0\n bus_add_driver+0x3ac/0x650\n driver_register+0x241/0x3d0\n mlxsw_sp_module_init+0xa2/0x174\n do_one_initcall+0xee/0x5f0\n kernel_init_freeable+0x45a/0x4de\n kernel_init+0x1f/0x210\n ret_from_fork+0x1f/0x30\n\nThe buggy address belongs to the object at ffff8881052f7800\n which belongs to the cache kmalloc-1k of size 1024\nThe buggy address is located 1016 bytes inside of\n 1024-byte region [ffff8881052f7800, ffff8881052f7c00)\nThe buggy address belongs to the page:\npage:0000000052355272 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1052f0\nhead:0000000052355272 order:3 compound_mapcount:0 compound_pincount:0\nflags: 0x200000000010200(slab|head|node=0|zone=2)\nraw: 0200000000010200 ffffea0005034800 0000000300000003 ffff888100041dc0\nraw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000\npage dumped because: kasan: bad access detected\n\nMemory state around the buggy address:\n ffff8881052f7a80: 00 00 00 00 00 00 04 fc fc fc fc fc fc fc fc fc\n ffff8881052f7b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n\u003effff8881052f7b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n                                                                ^\n ffff8881052f7c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n ffff8881052f7c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n\n[2] https://lore.kernel.org/linux-pm/9aca37cb-1629-5c67-\n---truncated---","modified":"2026-03-15T22:43:13.324155Z","published":"2024-05-22T07:15:09.340Z","related":["ALSA-2024:7000","ALSA-2024:7001","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-2024:2185-1","SUSE-SU-2024:2189-1","SUSE-SU-2024:2190-1","SUSE-SU-2024:2892-1","SUSE-SU-2024:2901-1","SUSE-SU-2024:2940-1"],"references":[{"type":"FIX","url":"https://git.kernel.org/stable/c/ae0993739e14a102d506aa09e11b0065f3144f10"},{"type":"FIX","url":"https://git.kernel.org/stable/c/df8e58716afb3bee2b59de66b1ba1033f2e26303"},{"type":"FIX","url":"https://git.kernel.org/stable/c/e59d839743b50cb1d3f42a786bea48cc5621d254"},{"type":"FIX","url":"https://git.kernel.org/stable/c/332fdf951df8b870e3da86b122ae304e2aabe88c"}],"affected":[{"database_specific":{"unresolved_ranges":[{"events":[{"introduced":"4.10"},{"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-2021-47441.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:L/A:H"}]}