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| author | Junrui Luo <moonafterrain@outlook.com> | 2026-06-04 15:34:25 +0800 |
|---|---|---|
| committer | Suzuki K Poulose <suzuki.poulose@arm.com> | 2026-06-04 09:56:13 +0100 |
| commit | 98495b5a4d77dd22e106f462b76e1093a55b29a7 (patch) | |
| tree | 6f412eb3620bf13cb7d70621c9d0f4a5112e3d59 /drivers/hwtracing | |
| parent | fa09f08ede3db3050ae16ae1ed92c902d0cada23 (diff) | |
| download | linux-next-98495b5a4d77dd22e106f462b76e1093a55b29a7.tar.gz linux-next-98495b5a4d77dd22e106f462b76e1093a55b29a7.zip | |
coresight: ultrasoc-smb: Fix OOB write in smb_sync_perf_buffer()
When the SMB sink is used as a perf AUX sink, smb_update_buffer() calls
smb_sync_perf_buffer() to copy hardware trace data into the perf AUX ring
buffer pages. It derives pg_idx = head >> PAGE_SHIFT from @head, which is
handle->head, and indexes dst_pages[pg_idx]. The pg_idx %= nr_pages
normalization is only applied after the first loop iteration.
This leaves the initial page index underived from the buffer size, which
can result in an out-of-bounds write past dst_pages[] when head exceeds
the AUX buffer size.
Normalize head modulo the AUX buffer size before deriving the page index
and offset, mirroring tmc_etr_sync_perf_buffer().
Fixes: 06f5c2926aaa ("drivers/coresight: Add UltraSoc System Memory Buffer driver")
Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/SYBPR01MB788156B3380A36835DB22290AF102@SYBPR01MB7881.ausprd01.prod.outlook.com
Diffstat (limited to 'drivers/hwtracing')
| -rw-r--r-- | drivers/hwtracing/coresight/ultrasoc-smb.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c index 5776f63468fa..20a950b9dd4f 100644 --- a/drivers/hwtracing/coresight/ultrasoc-smb.c +++ b/drivers/hwtracing/coresight/ultrasoc-smb.c @@ -337,6 +337,7 @@ static void smb_sync_perf_buffer(struct smb_drv_data *drvdata, unsigned long to_copy; long pg_idx, pg_offset; + head %= (unsigned long)buf->nr_pages << PAGE_SHIFT; pg_idx = head >> PAGE_SHIFT; pg_offset = head & (PAGE_SIZE - 1); |