On Sun, Jul 08, 2018 at 01:50:21PM +0300, Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
>
> User's supplied index is checked again total number of system pages,
> but this number already includes num_static_sys_pages, so addition
> of that value to supplied index causes to below error while trying
> to access sys_pages[].
>
> BUG: KASAN: slab-out-of-bounds in bfregn_to_uar_index+0x34f/0x400
> Read of size 4 at addr ffff880065561904 by task syz-executor446/314
>
> CPU: 0 PID: 314 Comm: syz-executor446 Not tainted 4.18.0-rc1+ #256
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.0-0-g63451fca13-prebuilt.qemu-project.org 04/01/2014
> Call Trace:
> dump_stack+0xef/0x17e
> print_address_description+0x83/0x3b0
> kasan_report+0x18d/0x4d0
> bfregn_to_uar_index+0x34f/0x400
> create_user_qp+0x272/0x227d
> create_qp_common+0x32eb/0x43e0
> mlx5_ib_create_qp+0x379/0x1ca0
> create_qp.isra.5+0xc94/0x22d0
> ib_uverbs_create_qp+0x21b/0x2a0
> ib_uverbs_write+0xc2c/0x1010
> vfs_write+0x1b0/0x550
> ksys_write+0xc6/0x1a0
> do_syscall_64+0xa7/0x590
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x433679
> Code: fd ff 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b 91 fd ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007fff2b3d8e48 EFLAGS: 00000217 ORIG_RAX: 0000000000000001
> RAX: ffffffffffffffda RBX: 00000000004002f8 RCX: 0000000000433679
> RDX: 0000000000000040 RSI: 0000000020000240 RDI: 0000000000000003
> RBP: 00000000006d4018 R08: 00000000004002f8 R09: 00000000004002f8
> R10: 00000000004002f8 R11: 0000000000000217 R12: 0000000000000000
> R13: 000000000040cb00 R14: 000000000040cb90 R15: 0000000000000006
>
> Allocated by task 314:
> kasan_kmalloc+0xa0/0xd0
> __kmalloc+0x1a9/0x510
> mlx5_ib_alloc_ucontext+0x966/0x2620
> ib_uverbs_get_context+0x23f/0xa60
> ib_uverbs_write+0xc2c/0x1010
> __vfs_write+0x10d/0x720
> vfs_write+0x1b0/0x550
> ksys_write+0xc6/0x1a0
> do_syscall_64+0xa7/0x590
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> Freed by task 1:
> __kasan_slab_free+0x12e/0x180
> kfree+0x159/0x630
> kvfree+0x37/0x50
> single_release+0x8e/0xf0
> __fput+0x2d8/0x900
> task_work_run+0x102/0x1f0
> exit_to_usermode_loop+0x159/0x1c0
> do_syscall_64+0x408/0x590
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> The buggy address belongs to the object at ffff880065561100
> which belongs to the cache kmalloc-4096 of size 4096
> The buggy address is located 2052 bytes inside of
> 4096-byte region [ffff880065561100, ffff880065562100)
> The buggy address belongs to the page:
> page:ffffea0001955800 count:1 mapcount:0 mapping:ffff88006c402480 index:0x0 compound_mapcount: 0
> flags: 0x4000000000008100(slab|head)
> raw: 4000000000008100 ffffea0001a7c000 0000000200000002 ffff88006c402480
> raw: 0000000000000000 0000000080070007 00000001ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
> ffff880065561800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ffff880065561880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> >ffff880065561900: 04 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ^
> ffff880065561980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff880065561a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>
> Cc: <stable@xxxxxxxxxxxxxxx> # 4.15
> Fixes: 1ee47ab3e8d8 ("IB/mlx5: Enable QP creation with a given blue flame index")
> Reported-by: Noa Osherovich <noaos@xxxxxxxxxxxx>
> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
> drivers/infiniband/hw/mlx5/mlx5_ib.h | 2 +-
> drivers/infiniband/hw/mlx5/qp.c | 15 ++++++++-------
> 2 files changed, 9 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> index f427406bffc5..3337e3d289b1 100644
> +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
> @@ -1361,6 +1361,6 @@ unsigned long mlx5_ib_get_xlt_emergency_page(void);
> void mlx5_ib_put_xlt_emergency_page(void);
>
> int bfregn_to_uar_index(struct mlx5_ib_dev *dev,
> - struct mlx5_bfreg_info *bfregi, int bfregn,
> + struct mlx5_bfreg_info *bfregi, u32 bfregn,
> bool dyn_bfreg);
> #endif /* MLX5_IB_H */
> diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
> index c566dff6ee6e..4ac132ba19a7 100644
> +++ b/drivers/infiniband/hw/mlx5/qp.c
> @@ -631,22 +631,23 @@ static void mlx5_ib_unlock_cqs(struct mlx5_ib_cq *send_cq,
> struct mlx5_ib_cq *recv_cq);
>
> int bfregn_to_uar_index(struct mlx5_ib_dev *dev,
> - struct mlx5_bfreg_info *bfregi, int bfregn,
> + struct mlx5_bfreg_info *bfregi, u32 bfregn,
> bool dyn_bfreg)
> {
> - int bfregs_per_sys_page;
> - int index_of_sys_page;
> - int offset;
> + unsigned int bfregs_per_sys_page;
> + u32 index_of_sys_page;
> + u32 offset;
>
> bfregs_per_sys_page = get_uars_per_sys_page(dev, bfregi->lib_uar_4k) *
> MLX5_NON_FP_BFREGS_PER_UAR;
> index_of_sys_page = bfregn / bfregs_per_sys_page;
>
> - if (index_of_sys_page >= bfregi->num_sys_pages)
> - return -EINVAL;
> -
> if (dyn_bfreg) {
> index_of_sys_page += bfregi->num_static_sys_pages;
> +
> + if (index_of_sys_page >= bfregi->num_sys_pages)
> + return -EINVAL;
This looks like the !dyn_bfreg path looses its range check though?
Should it be like this?
@@ -653,16 +653,19 @@ int bfregn_to_uar_index(struct mlx5_ib_dev *dev,
MLX5_NON_FP_BFREGS_PER_UAR;
index_of_sys_page = bfregn / bfregs_per_sys_page;
- if (index_of_sys_page >= bfregi->num_sys_pages)
- return -EINVAL;
-
if (dyn_bfreg) {
index_of_sys_page += bfregi->num_static_sys_pages;
+ if (index_of_sys_page >= bfregi->num_sys_pages)
+ return -EINVAL;
+
if (bfregn > bfregi->num_dyn_bfregs ||
bfregi->sys_pages[index_of_sys_page] == MLX5_IB_INVALID_UAR_INDEX) {
mlx5_ib_dbg(dev, "Invalid dynamic uar index\n");
return -EINVAL;
}
+ } else {
+ if (index_of_sys_page >= bfregi->num_sys_pages)
+ return -EINVAL;
}
offset = bfregn % bfregs_per_sys_page / MLX5_NON_FP_BFREGS_PER_UAR;
Jason
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