CVE-2024-43901

Description

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix NULL pointer dereference for DTN log in DCN401 When users run the command: cat /sys/kernel/debug/dri/0/amdgpu_dm_dtn_log The following NULL pointer dereference happens: [ +0.000003] BUG: kernel NULL pointer dereference, address: NULL [ +0.000005] #PF: supervisor instruction fetch in kernel mode [ +0.000002] #PF: error_code(0x0010) - not-present page [ +0.000002] PGD 0 P4D 0 [ +0.000004] Oops: 0010 [#1] PREEMPT SMP NOPTI [ +0.000003] RIP: 0010:0x0 [ +0.000008] Code: Unable to access opcode bytes at 0xffffffffffffffd6. [...] [ +0.000002] PKRU: 55555554 [ +0.000002] Call Trace: [ +0.000002] <TASK> [ +0.000003] ? show_regs+0x65/0x70 [ +0.000006] ? __die+0x24/0x70 [ +0.000004] ? page_fault_oops+0x160/0x470 [ +0.000006] ? do_user_addr_fault+0x2b5/0x690 [ +0.000003] ? prb_read_valid+0x1c/0x30 [ +0.000005] ? exc_page_fault+0x8c/0x1a0 [ +0.000005] ? asm_exc_page_fault+0x27/0x30 [ +0.000012] dcn10_log_color_state+0xf9/0x510 [amdgpu] [ +0.000306] ? srso_alias_return_thunk+0x5/0xfbef5 [ +0.000003] ? vsnprintf+0x2fb/0x600 [ +0.000009] dcn10_log_hw_state+0xfd0/0xfe0 [amdgpu] [ +0.000218] ? __mod_memcg_lruvec_state+0xe8/0x170 [ +0.000008] ? srso_alias_return_thunk+0x5/0xfbef5 [ +0.000002] ? debug_smp_processor_id+0x17/0x20 [ +0.000003] ? srso_alias_return_thunk+0x5/0xfbef5 [ +0.000002] ? srso_alias_return_thunk+0x5/0xfbef5 [ +0.000002] ? set_ptes.isra.0+0x2b/0x90 [ +0.000004] ? srso_alias_return_thunk+0x5/0xfbef5 [ +0.000002] ? _raw_spin_unlock+0x19/0x40 [ +0.000004] ? srso_alias_return_thunk+0x5/0xfbef5 [ +0.000002] ? do_anonymous_page+0x337/0x700 [ +0.000004] dtn_log_read+0x82/0x120 [amdgpu] [ +0.000207] full_proxy_read+0x66/0x90 [ +0.000007] vfs_read+0xb0/0x340 [ +0.000005] ? __count_memcg_events+0x79/0xe0 [ +0.000002] ? srso_alias_return_thunk+0x5/0xfbef5 [ +0.000003] ? count_memcg_events.constprop.0+0x1e/0x40 [ +0.000003] ? handle_mm_fault+0xb2/0x370 [ +0.000003] ksys_read+0x6b/0xf0 [ +0.000004] __x64_sys_read+0x19/0x20 [ +0.000003] do_syscall_64+0x60/0x130 [ +0.000004] entry_SYSCALL_64_after_hwframe+0x6e/0x76 [ +0.000003] RIP: 0033:0x7fdf32f147e2 [...] This error happens when the color log tries to read the gamut remap information from DCN401 which is not initialized in the dcn401_dpp_funcs which leads to a null pointer dereference. This commit addresses this issue by adding a proper guard to access the gamut_remap callback in case the specific ASIC did not implement this function.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

• https://git.kernel.org/stable/c/1e68b7ce6bc6073579fe8713ec6b85aa9cd2e351 ↗
• https://git.kernel.org/stable/c/5af757124792817f8eb1bd0c80ad60fab519586b ↗