lkml.org 
[lkml]   [2022]   [Dec]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH] ntfs3: fix NULL pointer dereference in 'ni_write_inode'
From
On 17.11.2022 13:19, Ye Bin wrote:
> From: Ye Bin <yebin10@huawei.com>
>
> Syzbot found the following issue:
> Unable to handle kernel NULL pointer dereference at virtual address 0000000000000016
> Mem abort info:
> ESR = 0x0000000096000006
> EC = 0x25: DABT (current EL), IL = 32 bits
> SET = 0, FnV = 0
> EA = 0, S1PTW = 0
> FSC = 0x06: level 2 translation fault
> Data abort info:
> ISV = 0, ISS = 0x00000006
> CM = 0, WnR = 0
> user pgtable: 4k pages, 48-bit VAs, pgdp=000000010af56000
> [0000000000000016] pgd=08000001090da003, p4d=08000001090da003, pud=08000001090ce003, pmd=0000000000000000
> Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP
> Modules linked in:
> CPU: 1 PID: 3036 Comm: syz-executor206 Not tainted 6.0.0-rc6-syzkaller-17739-g16c9f284e746 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
> pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
> pc : is_rec_inuse fs/ntfs3/ntfs.h:313 [inline]
> pc : ni_write_inode+0xac/0x798 fs/ntfs3/frecord.c:3232
> lr : ni_write_inode+0xa0/0x798 fs/ntfs3/frecord.c:3226
> sp : ffff8000126c3800
> x29: ffff8000126c3860 x28: 0000000000000000 x27: ffff0000c8b02000
> x26: ffff0000c7502320 x25: ffff0000c7502288 x24: 0000000000000000
> x23: ffff80000cbec91c x22: ffff0000c8b03000 x21: ffff0000c8b02000
> x20: 0000000000000001 x19: ffff0000c75024d8 x18: 00000000000000c0
> x17: ffff80000dd1b198 x16: ffff80000db59158 x15: ffff0000c4b6b500
> x14: 00000000000000b8 x13: 0000000000000000 x12: ffff0000c4b6b500
> x11: ff80800008be1b60 x10: 0000000000000000 x9 : ffff0000c4b6b500
> x8 : 0000000000000000 x7 : ffff800008be1b50 x6 : 0000000000000000
> x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
> x2 : 0000000000000008 x1 : 0000000000000001 x0 : 0000000000000000
> Call trace:
> is_rec_inuse fs/ntfs3/ntfs.h:313 [inline]
> ni_write_inode+0xac/0x798 fs/ntfs3/frecord.c:3232
> ntfs_evict_inode+0x54/0x84 fs/ntfs3/inode.c:1744
> evict+0xec/0x334 fs/inode.c:665
> iput_final fs/inode.c:1748 [inline]
> iput+0x2c4/0x324 fs/inode.c:1774
> ntfs_new_inode+0x7c/0xe0 fs/ntfs3/fsntfs.c:1660
> ntfs_create_inode+0x20c/0xe78 fs/ntfs3/inode.c:1278
> ntfs_create+0x54/0x74 fs/ntfs3/namei.c:100
> lookup_open fs/namei.c:3413 [inline]
> open_last_lookups fs/namei.c:3481 [inline]
> path_openat+0x804/0x11c4 fs/namei.c:3688
> do_filp_open+0xdc/0x1b8 fs/namei.c:3718
> do_sys_openat2+0xb8/0x22c fs/open.c:1311
> do_sys_open fs/open.c:1327 [inline]
> __do_sys_openat fs/open.c:1343 [inline]
> __se_sys_openat fs/open.c:1338 [inline]
> __arm64_sys_openat+0xb0/0xe0 fs/open.c:1338
> __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
> invoke_syscall arch/arm64/kernel/syscall.c:52 [inline]
> el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142
> do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206
> el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636
> el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654
> el0t_64_sync+0x18c/0x190
> Code: 97dafee4 340001b4 f9401328 2a1f03e0 (79402d14)
> ---[ end trace 0000000000000000 ]---
>
> Above issue may happens as follows:
> ntfs_new_inode
> mi_init
> mi->mrec = kmalloc(sbi->record_size, GFP_NOFS); -->failed to allocate memory
> if (!mi->mrec)
> return -ENOMEM;
> iput
> iput_final
> evict
> ntfs_evict_inode
> ni_write_inode
> is_rec_inuse(ni->mi.mrec)-> As 'ni->mi.mrec' is NULL trigger NULL-ptr-deref
>
> To solve above issue if new inode failed make inode bad before call 'iput()' in
> 'ntfs_new_inode()'.
>
> Reported-by: syzbot+f45957555ed4a808cc7a@syzkaller.appspotmail.com
> Signed-off-by: Ye Bin <yebin10@huawei.com>
> ---
> fs/ntfs3/fsntfs.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/ntfs3/fsntfs.c b/fs/ntfs3/fsntfs.c
> index 567563771bf8..8de861ddec60 100644
> --- a/fs/ntfs3/fsntfs.c
> +++ b/fs/ntfs3/fsntfs.c
> @@ -1683,6 +1683,7 @@ struct ntfs_inode *ntfs_new_inode(struct ntfs_sb_info *sbi, CLST rno, bool dir)
>
> out:
> if (err) {
> + make_bad_inode(inode);
> iput(inode);
> ni = ERR_PTR(err);
> }
Thanks for patch, applied!

\
 
 \ /
  Last update: 2023-03-26 23:20    [W:0.042 / U:0.340 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site