[PATCH 5.12 371/677] drm/amd/display: Free local data after use

From: Greg Kroah-Hartman
Date: Wed May 12 2021 - 14:47:09 EST


From: Victor Lu <victorchengchi.lu@xxxxxxx>

[ Upstream commit 616cf23b6cf40ad6f03ffbddfa1b6c4eb68d8ae1 ]

Fixes the following memory leak in dc_link_construct():

unreferenced object 0xffffa03e81471400 (size 1024):
comm "amd_module_load", pid 2486, jiffies 4294946026 (age 10.544s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<000000000bdf5c4a>] kmem_cache_alloc_trace+0x30a/0x4a0
[<00000000e7c59f0e>] link_create+0xce/0xac0 [amdgpu]
[<000000002fb6c072>] dc_create+0x370/0x720 [amdgpu]
[<000000000094d1f3>] amdgpu_dm_init+0x18e/0x17a0 [amdgpu]
[<00000000bec048fd>] dm_hw_init+0x12/0x20 [amdgpu]
[<00000000a2bb7cf6>] amdgpu_device_init+0x1463/0x1e60 [amdgpu]
[<0000000032d3bb13>] amdgpu_driver_load_kms+0x5b/0x330 [amdgpu]
[<00000000a27834f9>] amdgpu_pci_probe+0x192/0x280 [amdgpu]
[<00000000fec7d291>] local_pci_probe+0x47/0xa0
[<0000000055dbbfa7>] pci_device_probe+0xe3/0x180
[<00000000815da970>] really_probe+0x1c4/0x4e0
[<00000000b4b6974b>] driver_probe_device+0x62/0x150
[<000000000f9ecc61>] device_driver_attach+0x58/0x60
[<000000000f65c843>] __driver_attach+0xd6/0x150
[<000000002f5e3683>] bus_for_each_dev+0x6a/0xc0
[<00000000a1cfc897>] driver_attach+0x1e/0x20

Fixes: 3a00c04212d1cf ("drm/amd/display/dc/core/dc_link: Move some local data from the stack to the heap")
Signed-off-by: Victor Lu <victorchengchi.lu@xxxxxxx>
Reviewed-by: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/amd/display/dc/core/dc_link.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link.c b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
index bd0101013ec8..440bf0a0e12a 100644
--- a/drivers/gpu/drm/amd/display/dc/core/dc_link.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link.c
@@ -1603,6 +1603,7 @@ static bool dc_link_construct(struct dc_link *link,
link->psr_settings.psr_version = DC_PSR_VERSION_UNSUPPORTED;

DC_LOG_DC("BIOS object table - %s finished successfully.\n", __func__);
+ kfree(info);
return true;
device_tag_fail:
link->link_enc->funcs->destroy(&link->link_enc);
--
2.30.2