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author | Ian Jackson <Ian.Jackson@eu.citrix.com> | 2012-11-14 11:46:07 +0000 |
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committer | Ian Jackson <Ian.Jackson@eu.citrix.com> | 2012-11-14 11:46:07 +0000 |
commit | 45cc0581c6515105147fbc27339d056e02782efb (patch) | |
tree | 0b8e748adefa3f4d41977a5b7cfd57960153c891 | |
parent | 33df3b4a744312c01a8fa9929f06d62a81f50c28 (diff) | |
download | xen-45cc0581c6515105147fbc27339d056e02782efb.tar.gz xen-45cc0581c6515105147fbc27339d056e02782efb.tar.bz2 xen-45cc0581c6515105147fbc27339d056e02782efb.zip |
compat/gnttab: Prevent infinite loop in compat code
c/s 20281:95ea2052b41b, which introduces Grant Table version 2
hypercalls introduces a vulnerability whereby the compat hypercall
handler can fall into an infinite loop.
If the watchdog is enabled, Xen will die after the timeout.
This is a security problem, XSA-24 / CVE-2012-4539.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
xen-unstable changeset: 26151:b64a7d868f06
Backport-requested-by: security@xen.org
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
-rw-r--r-- | xen/common/compat/grant_table.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/xen/common/compat/grant_table.c b/xen/common/compat/grant_table.c index edd20c6bd3..32cd2bf5eb 100644 --- a/xen/common/compat/grant_table.c +++ b/xen/common/compat/grant_table.c @@ -318,6 +318,8 @@ int compat_grant_table_op(unsigned int cmd, #undef XLAT_gnttab_get_status_frames_HNDL_frame_list if ( unlikely(__copy_to_guest(cmp_uop, &cmp.get_status, 1)) ) rc = -EFAULT; + else + i = 1; } break; } |