Revision 73223e4e2e3867ebf033a5a8eb2e5df0158ccc99 authored by zhong jiang on 18 August 2017, 22:16:24 UTC, committed by Linus Torvalds on 18 August 2017, 22:32:02 UTC
I hit a use after free issue when executing trinity and repoduced it with KASAN enabled. The related call trace is as follows. BUG: KASan: use after free in SyS_get_mempolicy+0x3c8/0x960 at addr ffff8801f582d766 Read of size 2 by task syz-executor1/798 INFO: Allocated in mpol_new.part.2+0x74/0x160 age=3 cpu=1 pid=799 __slab_alloc+0x768/0x970 kmem_cache_alloc+0x2e7/0x450 mpol_new.part.2+0x74/0x160 mpol_new+0x66/0x80 SyS_mbind+0x267/0x9f0 system_call_fastpath+0x16/0x1b INFO: Freed in __mpol_put+0x2b/0x40 age=4 cpu=1 pid=799 __slab_free+0x495/0x8e0 kmem_cache_free+0x2f3/0x4c0 __mpol_put+0x2b/0x40 SyS_mbind+0x383/0x9f0 system_call_fastpath+0x16/0x1b INFO: Slab 0xffffea0009cb8dc0 objects=23 used=8 fp=0xffff8801f582de40 flags=0x200000000004080 INFO: Object 0xffff8801f582d760 @offset=5984 fp=0xffff8801f582d600 Bytes b4 ffff8801f582d750: ae 01 ff ff 00 00 00 00 5a 5a 5a 5a 5a 5a 5a 5a ........ZZZZZZZZ Object ffff8801f582d760: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk Object ffff8801f582d770: 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkk. Redzone ffff8801f582d778: bb bb bb bb bb bb bb bb ........ Padding ffff8801f582d8b8: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ Memory state around the buggy address: ffff8801f582d600: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801f582d680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801f582d700: fc fc fc fc fc fc fc fc fc fc fc fc fb fb fb fc !shared memory policy is not protected against parallel removal by other thread which is normally protected by the mmap_sem. do_get_mempolicy, however, drops the lock midway while we can still access it later. Early premature up_read is a historical artifact from times when put_user was called in this path see https://lwn.net/Articles/124754/ but that is gone since 8bccd85ffbaf ("[PATCH] Implement sys_* do_* layering in the memory policy layer."). but when we have the the current mempolicy ref count model. The issue was introduced accordingly. Fix the issue by removing the premature release. Link: http://lkml.kernel.org/r/1502950924-27521-1-git-send-email-zhongjiang@huawei.com Signed-off-by: zhong jiang <zhongjiang@huawei.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: <stable@vger.kernel.org> [2.6+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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quirks.h
#ifndef __USBAUDIO_QUIRKS_H
#define __USBAUDIO_QUIRKS_H
struct audioformat;
struct snd_usb_endpoint;
struct snd_usb_substream;
int snd_usb_create_quirk(struct snd_usb_audio *chip,
struct usb_interface *iface,
struct usb_driver *driver,
const struct snd_usb_audio_quirk *quirk);
int snd_usb_apply_interface_quirk(struct snd_usb_audio *chip,
int iface,
int altno);
int snd_usb_apply_boot_quirk(struct usb_device *dev,
struct usb_interface *intf,
const struct snd_usb_audio_quirk *quirk,
unsigned int usb_id);
void snd_usb_set_format_quirk(struct snd_usb_substream *subs,
struct audioformat *fmt);
bool snd_usb_get_sample_rate_quirk(struct snd_usb_audio *chip);
int snd_usb_is_big_endian_format(struct snd_usb_audio *chip,
struct audioformat *fp);
void snd_usb_endpoint_start_quirk(struct snd_usb_endpoint *ep);
void snd_usb_set_interface_quirk(struct usb_device *dev);
void snd_usb_ctl_msg_quirk(struct usb_device *dev, unsigned int pipe,
__u8 request, __u8 requesttype, __u16 value,
__u16 index, void *data, __u16 size);
int snd_usb_select_mode_quirk(struct snd_usb_substream *subs,
struct audioformat *fmt);
u64 snd_usb_interface_dsd_format_quirks(struct snd_usb_audio *chip,
struct audioformat *fp,
unsigned int sample_bytes);
#endif /* __USBAUDIO_QUIRKS_H */
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