Re: [PATCH] nvme: fix memory allocator in nvme_pr_read_keys()

[Sungwoo Kim]

Gentle ping.

On Sun, Feb 15, 2026 at 7:35 PM Sungwoo Kim <iam@xxxxxxxxxxxx> wrote:
>
> If IOC_PR_READ_KEYS is called with num_keys == PR_KEYS_MAX,
> nvme_pr_read_keys() may request more than 4MB memory via kzalloc().
> This always fails since kzalloc() does not allocate memory more than
> 4MB. As a result, ioctl() fails with ENOMEM, which is incorrect.
> To fix this, use kvzalloc() instead of kzalloc().
>
> WARNING: mm/page_alloc.c:5216 at __alloc_frozen_pages_noprof+0x5aa/0x2300 mm/page_alloc.c:5216, CPU#1: syz-executor117/272
> Modules linked in:
> CPU: 1 UID: 0 PID: 272 Comm: syz-executor117 Not tainted 6.19.0 #1 PREEMPT(voluntary)
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014
> RIP: 0010:__alloc_frozen_pages_noprof+0x5aa/0x2300 mm/page_alloc.c:5216
> Code: ff 83 bd a8 fe ff ff 0a 0f 86 69 fb ff ff 0f b6 1d f9 f9 c4 04 80 fb 01 0f 87 3b 76 30 ff 83 e3 01 75 09 c6 05 e4 f9 c4 04 01 <0f> 0b 48 c7 85 70 fe ff ff 00 00 00 00 e9 8f fd ff ff 31 c0 e9 0d
> RSP: 0018:ffffc90000fcf450 EFLAGS: 00010246
> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffff920001f9ea0
> RDX: 0000000000000000 RSI: 000000000000000b RDI: 0000000000040dc0
> RBP: ffffc90000fcf648 R08: ffff88800b6c3380 R09: 0000000000000001
> R10: ffffc90000fcf840 R11: ffff88807ffad280 R12: 0000000000000000
> R13: 0000000000040dc0 R14: 0000000000000001 R15: ffffc90000fcf620
> FS:  0000555565db33c0(0000) GS:ffff8880be26c000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000000002000000c CR3: 0000000003b72000 CR4: 00000000000006f0
> Call Trace:
>  <TASK>
>  alloc_pages_mpol+0x236/0x4d0 mm/mempolicy.c:2486
>  alloc_frozen_pages_noprof+0x149/0x180 mm/mempolicy.c:2557
>  ___kmalloc_large_node+0x10c/0x140 mm/slub.c:5598
>  __kmalloc_large_node_noprof+0x25/0xc0 mm/slub.c:5629
>  __do_kmalloc_node mm/slub.c:5645 [inline]
>  __kmalloc_noprof+0x483/0x6f0 mm/slub.c:5669
>  kmalloc_noprof include/linux/slab.h:961 [inline]
>  kzalloc_noprof include/linux/slab.h:1094 [inline]
>  nvme_pr_read_keys+0x8f/0x4c0 drivers/nvme/host/pr.c:245
>  blkdev_pr_read_keys block/ioctl.c:456 [inline]
>  blkdev_common_ioctl+0x1b71/0x29b0 block/ioctl.c:730
>  blkdev_ioctl+0x299/0x700 block/ioctl.c:786
>  vfs_ioctl fs/ioctl.c:51 [inline]
>  __do_sys_ioctl fs/ioctl.c:597 [inline]
>  __se_sys_ioctl fs/ioctl.c:583 [inline]
>  __x64_sys_ioctl+0x1bf/0x220 fs/ioctl.c:583
>  x64_sys_call+0x1280/0x21b0 mnt/fuzznvme_1/fuzznvme/linux-build/v6.19/./arch/x86/include/generated/asm/syscalls_64.h:17
>  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>  do_syscall_64+0x71/0x330 arch/x86/entry/syscall_64.c:94
>  entry_SYSCALL_64_after_hwframe+0x76/0x7e
> RIP: 0033:0x7fb893d3108d
> Code: 28 c3 e8 46 1e 00 00 66 0f 1f 44 00 00 f3 0f 1e fa 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007ffff61f2f38 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 00007ffff61f3138 RCX: 00007fb893d3108d
> RDX: 0000000020000040 RSI: 00000000c01070ce RDI: 0000000000000003
> RBP: 0000000000000001 R08: 0000000000000000 R09: 00007ffff61f3138
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
> R13: 00007ffff61f3128 R14: 00007fb893dae530 R15: 0000000000000001
>  </TASK>
>
> Fixes: 5fd96a4e15de (nvme: Add pr_ops read_keys support)
> Acked-by: Chao Shi <cshi008@xxxxxxx>
> Acked-by: Weidong Zhu <weizhu@xxxxxxx>
> Acked-by: Dave Tian <daveti@xxxxxxxxxx>
> Signed-off-by: Sungwoo Kim <iam@xxxxxxxxxxxx>
> ---
>  drivers/nvme/host/pr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/nvme/host/pr.c b/drivers/nvme/host/pr.c
> index ad2ecc2f4..5394b6cb0 100644
> --- a/drivers/nvme/host/pr.c
> +++ b/drivers/nvme/host/pr.c
> @@ -242,7 +242,7 @@ static int nvme_pr_read_keys(struct block_device *bdev,
>         if (rse_len > U32_MAX)
>                 return -EINVAL;
>
> -       rse = kzalloc(rse_len, GFP_KERNEL);
> +       rse = kvzalloc(rse_len, GFP_KERNEL);
>         if (!rse)
>                 return -ENOMEM;
>
> --
> 2.47.3
>