Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: dma-buf: fix UAF in dma_buf_fd() tracepoint Once FD_ADD() returns, the fd is live in the file descriptor table and a thread sharing that table can close() it before DMA_BUF_TRACE() runs. The close drops the last reference, __fput() frees the dma_buf, and the tracepoint then dereferences dmabuf to take dmabuf->name_lock -- slab-use-after-free. Split FD_ADD() back into get_unused_fd_flags() + fd_install() and emit the tracepoint between them. While the fdtable slot is reserved with a NULL file pointer, a racing close() returns -EBADF without entering __fput(), so the dma_buf stays alive across the trace. Same approach as commit 2d76319c4cbb ("dma-buf: fix UAF in dma_buf_put() tracepoint"). This undoes the FD_ADD() conversion done in commit 34dfce523c90 ("dma: convert dma_buf_fd() to FD_ADD()"); FD_ADD() has no place to hook the tracepoint safely.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 281a226314238e8adb08d11b765347687ffb38b9 before b569f86e2f8dbf6f11d31d3de794d22e18098b23; affected 281a226314238e8adb08d11b765347687ffb38b9 before ead6680f354f83966c796fc7f9463a3171789616 |
| Linux / Linux | affected 7.0; unaffected 0 before 7.0; unaffected 7.0.12 through 7.0.*; unaffected 7.1 through * |
CWE
No CWE identifiers supplied.