CVE-2026-80592

Summary

In the Linux kernel, the following vulnerability has been resolved:

samples/damon/mtier: fail early if address range parameters are invalid

The comment on top of struct damon_region clearly says that

For any use case, @ar should be non-zero positive size.

which is now verified in damon_verify_new_region() if the kernel is built with DAMON_DEBUG_SANITY.

The WARN_ONCE() can be triggered if the mtier sample module is enabled before node{0,1}_{start,end}_addr have been properly initialized, which is obviously not good.

————[ cut here ]———— start 0 >= end 0 WARNING: mm/damon/core.c:217 at damon_new_region+0xf4/0x118, CPU#59: bash/341468 Call trace: damon_new_region+0xf4/0x118 (P) damon_set_regions+0xfc/0x3c0 damon_sample_mtier_build_ctx+0xe8/0x3a8 damon_sample_mtier_start+0x1c/0x90 damon_sample_mtier_enable_store+0x98/0xb0 param_attr_store+0xb4/0x128 module_attr_store+0x2c/0x50 sysfs_kf_write+0x58/0x90 kernfs_fop_write_iter+0x16c/0x238 vfs_write+0x2c0/0x370 ksys_write+0x74/0x118 __arm64_sys_write+0x24/0x38 invoke_syscall+0xa8/0x118 el0_svc_common.constprop.0+0x48/0xf0 do_el0_svc+0x24/0x38 el0_svc+0x54/0x370 el0t_64_sync_handler+0xa0/0xe8 el0t_64_sync+0x1ac/0x1b0 —[ end trace 0000000000000000 ]—

Note that the same issue can happen if detect_node_addresses is true, and node 0 or 1 is memoryless. Fix it together by checking the validity of parameters right before damon_new_region() and fail early if they're invalid.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux82a08bde3cf7bbbe90de57baa181bebf676582c7 < 9d360fb820a3b9576d155e720ec44fef54d2efb5affected
LinuxLinux82a08bde3cf7bbbe90de57baa181bebf676582c7 < db20589d7b248211f63f4a7f642a49c0832b13aeaffected
LinuxLinux82a08bde3cf7bbbe90de57baa181bebf676582c7 < 7746d72c64054976887928d64d2caf25c5a6dcc0affected
LinuxLinux6.16affected
LinuxLinux0 < 6.16unaffected
LinuxLinux6.18.40 <= 6.18.*unaffected
LinuxLinux7.1.5 <= 7.1.*unaffected
LinuxLinux7.2 <= *unaffected

Weaknesses

References