[PATCH openEuler-1.0-LTS V1 0/2] hulk-4.19-fix-CVE-2022-49989
hulk-4.19-fix-CVE-2022-49989 Juergen Gross (1): xen/privcmd: fix error exit of privcmd_ioctl_dm_op() Souptick Joarder (1): xen/privcmd: Corrected error handling path drivers/xen/privcmd.c | 42 +++++++++++++++++++++--------------------- 1 file changed, 21 insertions(+), 21 deletions(-) -- 2.25.1
From: Souptick Joarder <jrdr.linux@gmail.com> mainline inclusion from mainline-v5.9-rc1 commit e398fb4bdf522abdeb8ddb61235bbf66065fc105 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICG959 CVE: CVE-2022-49989 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Previously, if lock_pages() end up partially mapping pages, it used to return -ERRNO due to which unlock_pages() have to go through each pages[i] till *nr_pages* to validate them. This can be avoided by passing correct number of partially mapped pages & -ERRNO separately, while returning from lock_pages() due to error. With this fix unlock_pages() doesn't need to validate pages[i] till *nr_pages* for error scenario and few condition checks can be ignored. Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: Paul Durrant <paul@xen.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Paul Durrant <xadimgnik@gmail.com> Link: https://lore.kernel.org/r/1594525195-28345-2-git-send-email-jrdr.linux@gmail... Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Cheng Yu <serein.chengyu@huawei.com> --- drivers/xen/privcmd.c | 31 +++++++++++++++---------------- 1 file changed, 15 insertions(+), 16 deletions(-) diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index b24ddac1604b..fc9f89a4d2b1 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -581,13 +581,13 @@ static long privcmd_ioctl_mmap_batch( static int lock_pages( struct privcmd_dm_op_buf kbufs[], unsigned int num, - struct page *pages[], unsigned int nr_pages) + struct page *pages[], unsigned int nr_pages, unsigned int *pinned) { unsigned int i; for (i = 0; i < num; i++) { unsigned int requested; - int pinned; + int page_count; requested = DIV_ROUND_UP( offset_in_page(kbufs[i].uptr) + kbufs[i].size, @@ -595,14 +595,15 @@ static int lock_pages( if (requested > nr_pages) return -ENOSPC; - pinned = get_user_pages_fast( + page_count = get_user_pages_fast( (unsigned long) kbufs[i].uptr, requested, FOLL_WRITE, pages); - if (pinned < 0) - return pinned; + if (page_count < 0) + return page_count; - nr_pages -= pinned; - pages += pinned; + *pinned += page_count; + nr_pages -= page_count; + pages += page_count; } return 0; @@ -612,13 +613,8 @@ static void unlock_pages(struct page *pages[], unsigned int nr_pages) { unsigned int i; - if (!pages) - return; - - for (i = 0; i < nr_pages; i++) { - if (pages[i]) - put_page(pages[i]); - } + for (i = 0; i < nr_pages; i++) + put_page(pages[i]); } static long privcmd_ioctl_dm_op(struct file *file, void __user *udata) @@ -631,6 +627,7 @@ static long privcmd_ioctl_dm_op(struct file *file, void __user *udata) struct xen_dm_op_buf *xbufs = NULL; unsigned int i; long rc; + unsigned int pinned = 0; if (copy_from_user(&kdata, udata, sizeof(kdata))) return -EFAULT; @@ -684,9 +681,11 @@ static long privcmd_ioctl_dm_op(struct file *file, void __user *udata) goto out; } - rc = lock_pages(kbufs, kdata.num, pages, nr_pages); - if (rc) + rc = lock_pages(kbufs, kdata.num, pages, nr_pages, &pinned); + if (rc < 0) { + nr_pages = pinned; goto out; + } for (i = 0; i < kdata.num; i++) { set_xen_guest_handle(xbufs[i].h, kbufs[i].uptr); -- 2.25.1
From: Juergen Gross <jgross@suse.com> mainline inclusion from mainline-v6.0-rc3 commit c5deb27895e017a0267de0a20d140ad5fcc55a54 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICG959 CVE: CVE-2022-49989 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- The error exit of privcmd_ioctl_dm_op() is calling unlock_pages() potentially with pages being NULL, leading to a NULL dereference. Additionally lock_pages() doesn't check for pin_user_pages_fast() having been completely successful, resulting in potentially not locking all pages into memory. This could result in sporadic failures when using the related memory in user mode. Fix all of that by calling unlock_pages() always with the real number of pinned pages, which will be zero in case pages being NULL, and by checking the number of pages pinned by pin_user_pages_fast() matching the expected number of pages. Cc: <stable@vger.kernel.org> Fixes: ab520be8cd5d ("xen/privcmd: Add IOCTL_PRIVCMD_DM_OP") Reported-by: Rustam Subkhankulov <subkhankulov@ispras.ru> Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Link: https://lore.kernel.org/r/20220825141918.3581-1-jgross@suse.com Signed-off-by: Juergen Gross <jgross@suse.com> Conflicts: drivers/xen/privcmd.c [The "git am" command reports a conflict due to the context of the function definition. There is no conflict where the code is modified, and then manually patched.] Signed-off-by: Cheng Yu <serein.chengyu@huawei.com> --- drivers/xen/privcmd.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index fc9f89a4d2b1..56f2458f012a 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -583,27 +583,30 @@ static int lock_pages( struct privcmd_dm_op_buf kbufs[], unsigned int num, struct page *pages[], unsigned int nr_pages, unsigned int *pinned) { - unsigned int i; + unsigned int i, off = 0; - for (i = 0; i < num; i++) { + for (i = 0; i < num; ) { unsigned int requested; int page_count; requested = DIV_ROUND_UP( offset_in_page(kbufs[i].uptr) + kbufs[i].size, - PAGE_SIZE); + PAGE_SIZE) - off; if (requested > nr_pages) return -ENOSPC; page_count = get_user_pages_fast( - (unsigned long) kbufs[i].uptr, + (unsigned long)kbufs[i].uptr + off * PAGE_SIZE, requested, FOLL_WRITE, pages); - if (page_count < 0) - return page_count; + if (page_count <= 0) + return page_count ? : -EFAULT; *pinned += page_count; nr_pages -= page_count; pages += page_count; + + off = (requested == page_count) ? 0 : off + page_count; + i += !off; } return 0; @@ -682,10 +685,8 @@ static long privcmd_ioctl_dm_op(struct file *file, void __user *udata) } rc = lock_pages(kbufs, kdata.num, pages, nr_pages, &pinned); - if (rc < 0) { - nr_pages = pinned; + if (rc < 0) goto out; - } for (i = 0; i < kdata.num; i++) { set_xen_guest_handle(xbufs[i].h, kbufs[i].uptr); @@ -697,7 +698,7 @@ static long privcmd_ioctl_dm_op(struct file *file, void __user *udata) xen_preemptible_hcall_end(); out: - unlock_pages(pages, nr_pages); + unlock_pages(pages, pinned); kfree(xbufs); kfree(pages); kfree(kbufs); -- 2.25.1
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