From e4845ae1fa4cebcc1a72b970e5f3375d5795a394 Mon Sep 17 00:00:00 2001
From: Sebin Sebastian <mailmesebin00@gmail.com>
Date: Sat, 30 Jul 2022 09:16:58 +0530
Subject: drm/amdgpu: double free error and freeing uninitialized null pointer
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Git-commit: ad2feebd71ff80532dff75756d1103f056358614
Patch-mainline: v6.0-rc2
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225 jsc#PED-2849
Fix a double free and an uninitialized pointer read error. Both tmp and
new are pointing at same address and both are freed which leads to
double free. Adding a check to verify if new and tmp are free in the
error_free label fixes the double free issue. new is not initialized to
null which also leads to a free on an uninitialized pointer.
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Suggested by: S. Amaranath <Amaranath.Somalapuram@amd.com>
Signed-off-by: Sebin Sebastian <mailmesebin00@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index e2eec985adb3..cb00c7d6f50b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -1705,7 +1705,7 @@ static ssize_t amdgpu_reset_dump_register_list_write(struct file *f,
{
struct amdgpu_device *adev = (struct amdgpu_device *)file_inode(f)->i_private;
char reg_offset[11];
- uint32_t *new, *tmp = NULL;
+ uint32_t *new = NULL, *tmp = NULL;
int ret, i = 0, len = 0;
do {
@@ -1747,7 +1747,8 @@ static ssize_t amdgpu_reset_dump_register_list_write(struct file *f,
ret = size;
error_free:
- kfree(tmp);
+ if (tmp != new)
+ kfree(tmp);
kfree(new);
return ret;
}
--
2.38.1