Commit 1383cb8103bb ("mlx4_core: allocate ICM memory in page size chunks") brought a regression caught in our regression suite, thanks to KASAN.
Note that mlx4_alloc_icm() is already able to try high order allocations and fallback to low-order allocations under high memory pressure. We only have to tweak gfp_mask a bit, to help falling back faster, without risking OOM killings. BUG: KASAN: slab-out-of-bounds in to_rdma_ah_attr+0x808/0x9e0 [mlx4_ib] Read of size 4 at addr ffff8817df584f68 by task qp_listing_test/92585 CPU: 38 PID: 92585 Comm: qp_listing_test Tainted: G O Call Trace: [<ffffffffba80d7bb>] dump_stack+0x4d/0x72 [<ffffffffb951dc5f>] print_address_description+0x6f/0x260 [<ffffffffb951e1c7>] kasan_report+0x257/0x370 [<ffffffffb951e339>] __asan_report_load4_noabort+0x19/0x20 [<ffffffffc0256d28>] to_rdma_ah_attr+0x808/0x9e0 [mlx4_ib] [<ffffffffc02785b3>] mlx4_ib_query_qp+0x1213/0x1660 [mlx4_ib] [<ffffffffc02dbfdb>] qpstat_print_qp+0x13b/0x500 [ib_uverbs] [<ffffffffc02dc3ea>] qpstat_seq_show+0x4a/0xb0 [ib_uverbs] [<ffffffffb95f125c>] seq_read+0xa9c/0x1230 [<ffffffffb96e0821>] proc_reg_read+0xc1/0x180 [<ffffffffb9577918>] __vfs_read+0xe8/0x730 [<ffffffffb9578057>] vfs_read+0xf7/0x300 [<ffffffffb95794d2>] SyS_read+0xd2/0x1b0 [<ffffffffb8e06b16>] do_syscall_64+0x186/0x420 [<ffffffffbaa00071>] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x7f851a7bb30d RSP: 002b:00007ffd09a758c0 EFLAGS: 00000293 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f84ff959440 RCX: 00007f851a7bb30d RDX: 000000000003fc00 RSI: 00007f84ff60a000 RDI: 000000000000000b RBP: 00007ffd09a75900 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000022 R11: 0000000000000293 R12: 0000000000000000 R13: 000000000003ffff R14: 000000000003ffff R15: 00007f84ff60a000 Allocated by task 4488: save_stack+0x46/0xd0 kasan_kmalloc+0xad/0xe0 __kmalloc+0x101/0x5e0 ib_register_device+0xc03/0x1250 [ib_core] mlx4_ib_add+0x27d6/0x4dd0 [mlx4_ib] mlx4_add_device+0xa9/0x340 [mlx4_core] mlx4_register_interface+0x16e/0x390 [mlx4_core] xhci_pci_remove+0x7a/0x180 [xhci_pci] do_one_initcall+0xa0/0x230 do_init_module+0x1b9/0x5a4 load_module+0x63e6/0x94c0 SYSC_init_module+0x1a4/0x1c0 SyS_init_module+0xe/0x10 do_syscall_64+0x186/0x420 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff8817df584f40 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 8 bytes to the right of 32-byte region [ffff8817df584f40, ffff8817df584f60) The buggy address belongs to the page: page:ffffea005f7d6100 count:1 mapcount:0 mapping:ffff8817df584000 index:0xffff8817df584fc1 flags: 0x880000000000100(slab) raw: 0880000000000100 ffff8817df584000 ffff8817df584fc1 000000010000003f raw: ffffea005f3ac0a0 ffffea005c476760 ffff8817fec00900 ffff883ff78d26c0 page dumped because: kasan: bad access detected page->mem_cgroup:ffff883ff78d26c0 Memory state around the buggy address: ffff8817df584e00: 00 03 fc fc fc fc fc fc 00 03 fc fc fc fc fc fc ffff8817df584e80: 00 00 00 04 fc fc fc fc 00 00 00 fc fc fc fc fc > ffff8817df584f00: fb fb fb fb fc fc fc fc 00 00 00 00 fc fc fc fc ^ ffff8817df584f80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ffff8817df585000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 1383cb8103bb ("mlx4_core: allocate ICM memory in page size chunks") Signed-off-by: Eric Dumazet <eduma...@google.com> Cc: John Sperbeck <jsperb...@google.com> Cc: Tarick Bedeir <tar...@google.com> Cc: Qing Huang <qing.hu...@oracle.com> Cc: Daniel Jurgens <dani...@mellanox.com> Cc: Zhu Yanjun <yanjun....@oracle.com> Cc: Tariq Toukan <tar...@mellanox.com> --- drivers/net/ethernet/mellanox/mlx4/icm.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/icm.c b/drivers/net/ethernet/mellanox/mlx4/icm.c index 685337d58276fc91baeeb64387c52985e1bc6dda..cae33d5c7dbd9ba7929adcf2127b104f6796fa5a 100644 --- a/drivers/net/ethernet/mellanox/mlx4/icm.c +++ b/drivers/net/ethernet/mellanox/mlx4/icm.c @@ -43,12 +43,13 @@ #include "fw.h" /* - * We allocate in page size (default 4KB on many archs) chunks to avoid high - * order memory allocations in fragmented/high usage memory situation. + * We allocate in as big chunks as we can, up to a maximum of 256 KB + * per chunk. Note that the chunks are not necessarily in contiguous + * physical memory. */ enum { - MLX4_ICM_ALLOC_SIZE = PAGE_SIZE, - MLX4_TABLE_CHUNK_SIZE = PAGE_SIZE, + MLX4_ICM_ALLOC_SIZE = 1 << 18, + MLX4_TABLE_CHUNK_SIZE = 1 << 18, }; static void mlx4_free_icm_pages(struct mlx4_dev *dev, struct mlx4_icm_chunk *chunk) @@ -135,6 +136,7 @@ struct mlx4_icm *mlx4_alloc_icm(struct mlx4_dev *dev, int npages, struct mlx4_icm *icm; struct mlx4_icm_chunk *chunk = NULL; int cur_order; + gfp_t mask; int ret; /* We use sg_set_buf for coherent allocs, which assumes low memory */ @@ -178,13 +180,16 @@ struct mlx4_icm *mlx4_alloc_icm(struct mlx4_dev *dev, int npages, while (1 << cur_order > npages) --cur_order; + mask = gfp_mask; + if (cur_order) + mask = (mask & ~__GFP_DIRECT_RECLAIM) | __GFP_NORETRY; if (coherent) ret = mlx4_alloc_icm_coherent(&dev->persist->pdev->dev, &chunk->mem[chunk->npages], - cur_order, gfp_mask); + cur_order, mask); else ret = mlx4_alloc_icm_pages(&chunk->mem[chunk->npages], - cur_order, gfp_mask, + cur_order, mask, dev->numa_node); if (ret) { -- 2.17.0.921.gf22659ad46-goog