On 10/19/26 20:31, Leon Romanovsky wrote: > On Tue, Oct 13, 2026 at 02:46:24PM +0300, Leon Romanovsky wrote: >> From: Leon Romanovsky <[email protected]> >> >> dma_buf_phys_vec_to_sgt() clears orig_nents to mark the returned table >> as DMA-only. Since sg_free_table() uses orig_nents to walk and free the >> scatterlist, dma_buf_free_sgt() leaks the allocation on every successful >> map/unmap cycle. >> >> Restore orig_nents from nents before freeing the table. The helper >> allocates the DMA list directly, so nents retains the allocation count, >> including for chained scatterlists. >> >> >> The reported kmemleak output was: >> >> KMEMLEAK LEAK: 2 driver-related leak(s) >> KMEMLEAK LEAK: unreferenced object 0xff11000125ceff00 (size 32): >> KMEMLEAK LEAK: comm dtr, pid 4432, jiffies 4295031027 >> KMEMLEAK LEAK: hex dump (first 32 bytes): >> KMEMLEAK LEAK: 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >> ................ >> KMEMLEAK LEAK: 00 00 01 00 28 38 00 00 00 10 00 00 00 00 00 00 >> ....(8.......... >> KMEMLEAK LEAK: backtrace (crc 4e8077f2): >> KMEMLEAK LEAK: __kmalloc_noprof+0x451/0x8b0 >> KMEMLEAK LEAK: __sg_alloc_table+0x2a0/0x4d0 >> KMEMLEAK LEAK: sg_alloc_table+0x24/0x170 >> KMEMLEAK LEAK: dma_buf_phys_vec_to_sgt+0x84f/0xed0 >> KMEMLEAK LEAK: 0xffffffffa1ad21a8 >> KMEMLEAK LEAK: dma_buf_map_attachment+0x138/0x690 >> KMEMLEAK LEAK: ib_umem_dmabuf_map_pages+0x249/0xc90 [ib_core] >> KMEMLEAK LEAK: 0xffffffffa138f8d2 >> KMEMLEAK LEAK: 0xffffffffa1396abe >> KMEMLEAK LEAK: 0xffffffffa1331a5f >> KMEMLEAK LEAK: 0xffffffffa13320dd >> KMEMLEAK LEAK: 0xffffffffa1ad696d >> KMEMLEAK LEAK: 0xffffffffa1acecc7 >> KMEMLEAK LEAK: 0xffffffffa1acfd17 >> KMEMLEAK LEAK: __x64_sys_ioctl+0x72c/0x11f0 >> KMEMLEAK LEAK: do_syscall_64+0xa1/0x4f0 >> KMEMLEAK LEAK: unreferenced object 0xff1100016dbf3a80 (size 32): >> KMEMLEAK LEAK: comm dtr, pid 4432, jiffies 4295034705 >> KMEMLEAK LEAK: hex dump (first 32 bytes): >> KMEMLEAK LEAK: 02 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >> ................ >> KMEMLEAK LEAK: 00 20 10 00 28 38 00 00 00 10 00 00 00 00 00 00 . >> ..(8.......... >> >> Fixes: 3aa31a8bb11e ("dma-buf: provide phys_vec to scatter-gather mapping >> routine") >> Signed-off-by: Leon Romanovsky <[email protected]> >> --- >> drivers/dma-buf/dma-buf-mapping.c | 2 ++ >> 1 file changed, 2 insertions(+) > > Reminder, thanks
I'm waiting for anybody familiar with the code to review this. Regards, Christian.
