From: Yunfei Dong <yunfei.dong@mediatek.com> stable inclusion from stable-v4.19.293 commit 7fc7f87725805197388ba749a1801df33000fa50 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ID0RG4 CVE: CVE-2023-53519 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 56b5c3e67b0f9af3f45cf393be048ee8d8a92694 ] Getting below error when using KCSAN to check the driver. Adding lock to protect parameter num_rdy when getting the value with function: v4l2_m2m_num_src_bufs_ready/v4l2_m2m_num_dst_bufs_ready. kworker/u16:3: [name:report&]BUG: KCSAN: data-race in v4l2_m2m_buf_queue kworker/u16:3: [name:report&] kworker/u16:3: [name:report&]read-write to 0xffffff8105f35b94 of 1 bytes by task 20865 on cpu 7: kworker/u16:3:  v4l2_m2m_buf_queue+0xd8/0x10c Signed-off-by: Pina Chen <pina.chen@mediatek.com> Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com> Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yin Tirui <yintirui@huawei.com> --- include/media/v4l2-mem2mem.h | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2-mem2mem.h index d655720e16a1..62c67e9e190c 100644 --- a/include/media/v4l2-mem2mem.h +++ b/include/media/v4l2-mem2mem.h @@ -405,7 +405,14 @@ void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, static inline unsigned int v4l2_m2m_num_src_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx) { - return m2m_ctx->out_q_ctx.num_rdy; + unsigned int num_buf_rdy; + unsigned long flags; + + spin_lock_irqsave(&m2m_ctx->out_q_ctx.rdy_spinlock, flags); + num_buf_rdy = m2m_ctx->out_q_ctx.num_rdy; + spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags); + + return num_buf_rdy; } /** @@ -417,7 +424,14 @@ unsigned int v4l2_m2m_num_src_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx) static inline unsigned int v4l2_m2m_num_dst_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx) { - return m2m_ctx->cap_q_ctx.num_rdy; + unsigned int num_buf_rdy; + unsigned long flags; + + spin_lock_irqsave(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags); + num_buf_rdy = m2m_ctx->cap_q_ctx.num_rdy; + spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags); + + return num_buf_rdy; } /** -- 2.43.0