* [PATCH] fs/ntfs3: Avoid UBSAN error on true_sectors_per_clst()
@ 2022-08-23 14:46 Shigeru Yoshida
2022-09-07 16:01 ` Shigeru Yoshida
2022-09-30 15:53 ` Konstantin Komarov
0 siblings, 2 replies; 3+ messages in thread
From: Shigeru Yoshida @ 2022-08-23 14:46 UTC (permalink / raw)
To: almaz.alexandrovich
Cc: ntfs3, linux-kernel, Shigeru Yoshida, Author : Randy Dunlap,
syzbot+35b87c668935bb55e666
syzbot reported UBSAN error as below:
[ 76.901829][ T6677] ================================================================================
[ 76.903908][ T6677] UBSAN: shift-out-of-bounds in fs/ntfs3/super.c:675:13
[ 76.905363][ T6677] shift exponent -247 is negative
This patch avoid this error.
Link: https://syzkaller.appspot.com/bug?id=b0299c09a14aababf0f1c862dd4ebc8ab9eb0179
Fixes: a3b774342fa7 (fs/ntfs3: validate BOOT sectors_per_clusters)
Cc: Author: Randy Dunlap <rdunlap@infradead.org>
Reported-by: syzbot+35b87c668935bb55e666@syzkaller.appspotmail.com
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
---
fs/ntfs3/super.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
index 47012c9bf505..adc4f73722b7 100644
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -672,7 +672,7 @@ static u32 true_sectors_per_clst(const struct NTFS_BOOT *boot)
if (boot->sectors_per_clusters <= 0x80)
return boot->sectors_per_clusters;
if (boot->sectors_per_clusters >= 0xf4) /* limit shift to 2MB max */
- return 1U << (0 - boot->sectors_per_clusters);
+ return 1U << -(s8)boot->sectors_per_clusters;
return -EINVAL;
}
--
2.37.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] fs/ntfs3: Avoid UBSAN error on true_sectors_per_clst()
2022-08-23 14:46 [PATCH] fs/ntfs3: Avoid UBSAN error on true_sectors_per_clst() Shigeru Yoshida
@ 2022-09-07 16:01 ` Shigeru Yoshida
2022-09-30 15:53 ` Konstantin Komarov
1 sibling, 0 replies; 3+ messages in thread
From: Shigeru Yoshida @ 2022-09-07 16:01 UTC (permalink / raw)
To: almaz.alexandrovich
Cc: ntfs3, linux-kernel, syoshida, rdunlap, syzbot+35b87c668935bb55e666
ping?
On Tue, 23 Aug 2022 23:46:25 +0900, Shigeru Yoshida wrote:
> syzbot reported UBSAN error as below:
>
> [ 76.901829][ T6677] ================================================================================
> [ 76.903908][ T6677] UBSAN: shift-out-of-bounds in fs/ntfs3/super.c:675:13
> [ 76.905363][ T6677] shift exponent -247 is negative
>
> This patch avoid this error.
>
> Link: https://syzkaller.appspot.com/bug?id=b0299c09a14aababf0f1c862dd4ebc8ab9eb0179
> Fixes: a3b774342fa7 (fs/ntfs3: validate BOOT sectors_per_clusters)
> Cc: Author: Randy Dunlap <rdunlap@infradead.org>
> Reported-by: syzbot+35b87c668935bb55e666@syzkaller.appspotmail.com
> Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
> ---
> fs/ntfs3/super.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
> index 47012c9bf505..adc4f73722b7 100644
> --- a/fs/ntfs3/super.c
> +++ b/fs/ntfs3/super.c
> @@ -672,7 +672,7 @@ static u32 true_sectors_per_clst(const struct NTFS_BOOT *boot)
> if (boot->sectors_per_clusters <= 0x80)
> return boot->sectors_per_clusters;
> if (boot->sectors_per_clusters >= 0xf4) /* limit shift to 2MB max */
> - return 1U << (0 - boot->sectors_per_clusters);
> + return 1U << -(s8)boot->sectors_per_clusters;
> return -EINVAL;
> }
>
> --
> 2.37.2
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] fs/ntfs3: Avoid UBSAN error on true_sectors_per_clst()
2022-08-23 14:46 [PATCH] fs/ntfs3: Avoid UBSAN error on true_sectors_per_clst() Shigeru Yoshida
2022-09-07 16:01 ` Shigeru Yoshida
@ 2022-09-30 15:53 ` Konstantin Komarov
1 sibling, 0 replies; 3+ messages in thread
From: Konstantin Komarov @ 2022-09-30 15:53 UTC (permalink / raw)
To: Shigeru Yoshida
Cc: ntfs3, linux-kernel, Author : Randy Dunlap, syzbot+35b87c668935bb55e666
On 8/23/22 17:46, Shigeru Yoshida wrote:
> syzbot reported UBSAN error as below:
>
> [ 76.901829][ T6677] ================================================================================
> [ 76.903908][ T6677] UBSAN: shift-out-of-bounds in fs/ntfs3/super.c:675:13
> [ 76.905363][ T6677] shift exponent -247 is negative
>
> This patch avoid this error.
>
> Link: https://syzkaller.appspot.com/bug?id=b0299c09a14aababf0f1c862dd4ebc8ab9eb0179
> Fixes: a3b774342fa7 (fs/ntfs3: validate BOOT sectors_per_clusters)
> Cc: Author: Randy Dunlap <rdunlap@infradead.org>
> Reported-by: syzbot+35b87c668935bb55e666@syzkaller.appspotmail.com
> Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
> ---
> fs/ntfs3/super.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
> index 47012c9bf505..adc4f73722b7 100644
> --- a/fs/ntfs3/super.c
> +++ b/fs/ntfs3/super.c
> @@ -672,7 +672,7 @@ static u32 true_sectors_per_clst(const struct NTFS_BOOT *boot)
> if (boot->sectors_per_clusters <= 0x80)
> return boot->sectors_per_clusters;
> if (boot->sectors_per_clusters >= 0xf4) /* limit shift to 2MB max */
> - return 1U << (0 - boot->sectors_per_clusters);
> + return 1U << -(s8)boot->sectors_per_clusters;
> return -EINVAL;
> }
>
Applied, thanks again for the patch!
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-09-30 15:53 UTC | newest]
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2022-08-23 14:46 [PATCH] fs/ntfs3: Avoid UBSAN error on true_sectors_per_clst() Shigeru Yoshida
2022-09-07 16:01 ` Shigeru Yoshida
2022-09-30 15:53 ` Konstantin Komarov
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