From: Nicholas Carlini __io_uring_show_fdinfo() iterates over pending SQEs and, for 128-byte SQEs on an IORING_SETUP_SQE_MIXED ring, needs to detect when the second half of the SQE would be past the end of the sq_sqes array. The current check tests (++sq_head & sq_mask) == 0, but sq_head is only incremented when a 128-byte SQE is encountered, not on every iteration. The actual array index is sq_idx = (i + sq_head) & sq_mask, which can be sq_mask (the last slot) while the wrap check passes. Fix by checking sq_idx directly. Keep the sq_head increment so the loop still skips the second half of the 128-byte SQE on the next iteration. Fixes: 1cba30bf9fdd ("io_uring: add support for IORING_SETUP_SQE_MIXED") Signed-off-by: Nicholas Carlini --- io_uring/fdinfo.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/io_uring/fdinfo.c b/io_uring/fdinfo.c index 80178b69e05a..6b5609f1db60 100644 --- a/io_uring/fdinfo.c +++ b/io_uring/fdinfo.c @@ -119,12 +119,13 @@ static void __io_uring_show_fdinfo(struct io_ring_ctx *ctx, struct seq_file *m) sq_idx); break; } - if ((++sq_head & sq_mask) == 0) { + if (sq_idx == sq_mask) { seq_printf(m, "%5u: corrupted sqe, wrapping 128B entry\n", sq_idx); break; } + sq_head++; sqe128 = true; } seq_printf(m, "%5u: opcode:%s, fd:%d, flags:%x, off:%llu, " -- 2.39.5