Re: [PATCH for-next v2] RDMA/rxe: Fix mr->map double free

From: Yanjun Zhu
Date: Sat Nov 19 2022 - 03:26:11 EST


在 2022/11/19 8:15, Jason Gunthorpe 写道:
On Sun, Oct 30, 2022 at 03:04:33AM +0000, Li Zhijian wrote:
rxe_mr_cleanup() which tries to free mr->map again will be called
when rxe_mr_init_user() fails.

[43895.939883] CPU: 0 PID: 4917 Comm: rdma_flush_serv Kdump: loaded Not tainted 6.1.0-rc1-roce-flush+ #25
[43895.942341] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[43895.945208] Call Trace:
[43895.946130] <TASK>
[43895.946931] dump_stack_lvl+0x45/0x5d
[43895.948049] panic+0x19e/0x349
[43895.949010] ? panic_print_sys_info.part.0+0x77/0x77
[43895.950356] ? asm_sysvec_apic_timer_interrupt+0x16/0x20
[43895.952589] ? preempt_count_sub+0x14/0xc0
[43895.953809] end_report.part.0+0x54/0x7c
[43895.954993] ? rxe_mr_cleanup+0x9d/0xf0 [rdma_rxe]
[43895.956406] kasan_report.cold+0xa/0xf
[43895.957668] ? rxe_mr_cleanup+0x9d/0xf0 [rdma_rxe]
[43895.959090] rxe_mr_cleanup+0x9d/0xf0 [rdma_rxe]
[43895.960502] __rxe_cleanup+0x10a/0x1e0 [rdma_rxe]
[43895.961983] rxe_reg_user_mr+0xb7/0xd0 [rdma_rxe]
[43895.963456] ib_uverbs_reg_mr+0x26a/0x480 [ib_uverbs]
[43895.964921] ? __lock_acquire+0x876/0x31e0
[43895.966182] ? ib_uverbs_ex_create_wq+0x630/0x630 [ib_uverbs]
[43895.967739] ? uverbs_fill_udata+0x1c6/0x330 [ib_uverbs]
[43895.969204] ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0x1a2/0x250 [ib_uverbs]
[43895.971126] ? ib_uverbs_handler_UVERBS_METHOD_QUERY_CONTEXT+0x1a0/0x1a0 [ib_uverbs]
[43895.973094] ? ib_uverbs_handler_UVERBS_METHOD_QUERY_CONTEXT+0x1a0/0x1a0 [ib_uverbs]
[43895.975096] ? uverbs_fill_udata+0x25f/0x330 [ib_uverbs]
[43895.976466] ib_uverbs_cmd_verbs+0x1397/0x15a0 [ib_uverbs]
[43895.977930] ? ib_uverbs_handler_UVERBS_METHOD_QUERY_CONTEXT+0x1a0/0x1a0 [ib_uverbs]
[43895.979937] ? uverbs_fill_udata+0x330/0x330 [ib_uverbs]

Please dont include timestamps in commit messages

@@ -163,9 +163,8 @@ int rxe_mr_init_user(struct rxe_dev *rxe, u64 start, u64 length, u64 iova,
pr_warn("%s: Unable to get virtual address\n",
__func__);
err = -ENOMEM;
- goto err_cleanup_map;
+ goto err_release_umem;
}
-

page_address() fails if this is a highmem system and the page hasn't
been kmap'd yet. So the right thing to do is to use kmap..

Sure.

sgt_append.sgt is allocated in this function ib_umem_get. And the function sg_alloc_append_table_from_pages is called to allocate memory.

147 struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr,
148 size_t size, int access)
149 {
...
230 ret = sg_alloc_append_table_from_pages(
231 &umem->sgt_append, page_list, pinned, 0,
232 pinned << PAGE_SHIFT, ib_dma_max_seg_size(device),
233 npages, GFP_KERNEL);
...

And it seems that it is not highmem.

So page_address will not be NULL?

As such, it is not necessary to test the return vaue of page_address?

If so, can we add a new commit to avoid testing of the return value of page_address?

Zhu Yanjun


But this looks right, so applied to for-next

Thanks,
Jason