'stream_enc_regs' array is an array of dcn10_stream_enc_registers
structures. The array is initialized with four elements, corresponding
to the four calls to stream_enc_regs() in the array initializer. This
means that valid indices for this array are 0, 1, 2, and 3.
The error message 'stream_enc_regs' 4 <= 5 below, is indicating that
there is an attempt to access this array with an index of 5, which is
out of bounds. This could lead to undefined behavior
Here, eng_id is used as an index to access the stream_enc_regs array. If
eng_id is 5, this would result in an out-of-bounds access on the
stream_enc_regs array.
Thus fixing Buffer overflow error in dcn301_stream_encoder_create
reported by Smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn301/dcn301_resource.c:1011 dcn301_stream_encoder_create() error: buffer overflow 'stream_enc_regs' 4 <= 5
Fixes: 3a83e4e64bb1 ("drm/amd/display: Add dcn3.01 support to DC (v2)")
Cc: Roman Li <Roman.Li@xxxxxxx>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@xxxxxxx>
Cc: Aurabindo Pillai <aurabindo.pillai@xxxxxxx>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
---
.../drm/amd/display/dc/resource/dcn301/dcn301_resource.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/resource/dcn301/dcn301_resource.c b/drivers/gpu/drm/amd/display/dc/resource/dcn301/dcn301_resource.c
index 511ff6b5b985..4a475a723191 100644
--- a/drivers/gpu/drm/amd/display/dc/resource/dcn301/dcn301_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/resource/dcn301/dcn301_resource.c
@@ -999,7 +999,7 @@ static struct stream_encoder *dcn301_stream_encoder_create(enum engine_id eng_id
vpg = dcn301_vpg_create(ctx, vpg_inst);
afmt = dcn301_afmt_create(ctx, afmt_inst);
- if (!enc1 || !vpg || !afmt) {
+ if (!enc1 || !vpg || !afmt || eng_id >= ARRAY_SIZE(stream_enc_regs)) {
kfree(enc1);
kfree(vpg);
kfree(afmt);
@@ -1007,10 +1007,9 @@ static struct stream_encoder *dcn301_stream_encoder_create(enum engine_id eng_id
}
dcn30_dio_stream_encoder_construct(enc1, ctx, ctx->dc_bios,
- eng_id, vpg, afmt,
- &stream_enc_regs[eng_id],
- &se_shift, &se_mask);
-
+ eng_id, vpg, afmt,
+ &stream_enc_regs[eng_id],
+ &se_shift, &se_mask);
return &enc1->base;
}
--
2.34.1
