Messages in this thread | | | Subject | Re: [PATCH net 2/2] octeontx2-pf: Fix a potential double free in otx2_sq_free_sqbs() | From | "Ziyang Xuan (William)" <> | Date | Fri, 2 Dec 2022 09:39:45 +0800 |
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> Hello, > > On Fri, 2022-11-25 at 15:45 +0800, Ziyang Xuan wrote: >> otx2_sq_free_sqbs() will be called twice when goto "err_free_nix_queues" >> label in otx2_init_hw_resources(). The first calling is within >> otx2_free_sq_res() at "err_free_nix_queues" label, and the second calling >> is at later "err_free_sq_ptrs" label. >> >> In otx2_sq_free_sqbs(), If sq->sqb_ptrs[i] is not 0, the memory page it >> points to will be freed, and sq->sqb_ptrs[i] do not be assigned 0 after >> memory page be freed. If otx2_sq_free_sqbs() is called twice, the memory >> page pointed by sq->sqb_ptrs[i] will be freeed twice. To fix the bug, >> assign 0 to sq->sqb_ptrs[i] after memory page be freed. >> >> Fixes: caa2da34fd25 ("octeontx2-pf: Initialize and config queues") >> Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com> >> --- >> drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c >> index 9e10e7471b88..5a25fe51d102 100644 >> --- a/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c >> +++ b/drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c >> @@ -1146,6 +1146,7 @@ void otx2_sq_free_sqbs(struct otx2_nic *pfvf) >> DMA_FROM_DEVICE, >> DMA_ATTR_SKIP_CPU_SYNC); >> put_page(virt_to_page(phys_to_virt(pa))); >> + sq->sqb_ptrs[sqb] = 0; > > The above looks not needed... >> } >> sq->sqb_count = 0; > > ... as this will prevent the next invocation of otx2_sq_free_sqbs() > from traversing and freeing any sq->sqb_ptrs[] element.
Yes, you are right. I did pay much attention to sq->sqb_ptrs[], and omitted the for loop condition.
Thank you!
> > Cheers, > > Paolo >> } > > > . >
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