On 2/4/19 5:22 PM, Qian Cai wrote:
> Booting up an arm64 server with CONFIG_VALIDATE_FS_PARSER=n triggers a
> out-of-bounds error below, due to the commit 2284cf59cbce ("hugetlbfs:
> Convert to fs_context") missed a terminator for hugetlb_param_specs[],
> and causes this loop in fs_lookup_key(),
>
> for (p = desc->specs; p->name; p++)
>
> could not exit properly due to p->name is never be NULL.
>
> [ 91.575203] BUG: KASAN: global-out-of-bounds in fs_lookup_key+0x60/0x94
> [ 91.581810] Read of size 8 at addr ffff200010deeb10 by task mount/2461
> [ 91.597350] Call trace:
> [ 91.597357] dump_backtrace+0x0/0x2b0
> [ 91.597361] show_stack+0x24/0x30
> [ 91.597373] dump_stack+0xc0/0xf8
> [ 91.623263] print_address_description+0x64/0x2b0
> [ 91.627965] kasan_report+0x150/0x1a4
> [ 91.627970] __asan_report_load8_noabort+0x30/0x3c
> [ 91.627974] fs_lookup_key+0x60/0x94
> [ 91.627977] fs_parse+0x104/0x990
> [ 91.627986] hugetlbfs_parse_param+0xc4/0x5e8
> [ 91.651081] vfs_parse_fs_param+0x2e4/0x378
> [ 91.658118] vfs_parse_fs_string+0xbc/0x12c
> [ 91.658122] do_mount+0x11f0/0x1640
> [ 91.658125] ksys_mount+0xc0/0xd0
> [ 91.658129] __arm64_sys_mount+0xcc/0xe4
> [ 91.658137] el0_svc_handler+0x28c/0x338
> [ 91.681740] el0_svc+0x8/0xc
>
> Fixes: 2284cf59cbce ("hugetlbfs: Convert to fs_context")
> Signed-off-by: Qian Cai <[email protected]>
Thanks for fixing this. Looks like a simple oversight when 2284cf59cbce
was added.
Reviewed-by: Mike Kravetz <[email protected]>
I just started looking at the new mount API now. It would be good if
David also took a look to make sure everything else is OK.
FYI David, the fs_parameter_spec example in the documentation (mount_api.txt)
is also missing a terminator.
--
Mike Kravetz
> ---
> fs/hugetlbfs/inode.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
> index abf0c2eb834e..4f352743930f 100644
> --- a/fs/hugetlbfs/inode.c
> +++ b/fs/hugetlbfs/inode.c
> @@ -81,6 +81,7 @@ static const struct fs_parameter_spec hugetlb_param_specs[]
> = {
> fsparam_string("pagesize", Opt_pagesize),
> fsparam_string("size", Opt_size),
> fsparam_u32 ("uid", Opt_uid),
> + {}
> };
>
> static const struct fs_parameter_description hugetlb_fs_parameters = {
>
