try_to_unmap_cluster() should lock_page() before mlocking Reference: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-3122
Upstream fix: https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/patch /?id=400fc13141fe947c38e8485ee9d37066d4533363 Signed-off-by: Sona Sarmadi <[email protected]> --- recipes-kernel/linux/files/mm-CVE-2014-3122.patch | 98 +++++++++++++++++++++++ recipes-kernel/linux/linux-qoriq_3.12.bb | 1 + 2 files changed, 99 insertions(+) create mode 100644 recipes-kernel/linux/files/mm-CVE-2014-3122.patch diff --git a/recipes-kernel/linux/files/mm-CVE-2014-3122.patch b/recipes-kernel/linux/files/mm-CVE-2014-3122.patch new file mode 100644 index 0000000..537d01b --- /dev/null +++ b/recipes-kernel/linux/files/mm-CVE-2014-3122.patch @@ -0,0 +1,98 @@ +commit 400fc13141fe947c38e8485ee9d37066d4533363 +Author: Vlastimil Babka <[email protected]> +Date: Mon Apr 7 15:37:50 2014 -0700 +Subject: mm: try_to_unmap_cluster() should lock_page() before mlocking + +commit 57e68e9cd65b4b8eb4045a1e0d0746458502554c upstream. + +A BUG_ON(!PageLocked) was triggered in mlock_vma_page() by Sasha Levin +fuzzing with trinity. The call site try_to_unmap_cluster() does not lock +the pages other than its check_page parameter (which is already locked). + +The BUG_ON in mlock_vma_page() is not documented and its purpose is +somewhat unclear, but apparently it serializes against page migration, +which could otherwise fail to transfer the PG_mlocked flag. This would +not be fatal, as the page would be eventually encountered again, but +NR_MLOCK accounting would become distorted nevertheless. This patch adds +a comment to the BUG_ON in mlock_vma_page() and munlock_vma_page() to that +effect. + +The call site try_to_unmap_cluster() is fixed so that for page != +check_page, trylock_page() is attempted (to avoid possible deadlocks as we +already have check_page locked) and mlock_vma_page() is performed only +upon success. If the page lock cannot be obtained, the page is left +without PG_mlocked, which is again not a problem in the whole unevictable +memory design. + +Fixes CVE-2014-3122 +Upstream-Status: Backport + +Signed-off-by: Vlastimil Babka <[email protected]> +Signed-off-by: Bob Liu <[email protected]> +Reported-by: Sasha Levin <[email protected]> +Cc: Wanpeng Li <[email protected]> +Cc: Michel Lespinasse <[email protected]> +Cc: KOSAKI Motohiro <[email protected]> +Acked-by: Rik van Riel <[email protected]> +Cc: David Rientjes <[email protected]> +Cc: Mel Gorman <[email protected]> +Cc: Hugh Dickins <[email protected]> +Cc: Joonsoo Kim <[email protected]> +Signed-off-by: Andrew Morton <[email protected]> +Signed-off-by: Linus Torvalds <[email protected]> +Signed-off-by: Jiri Slaby <[email protected]> +Signed-off-by: Sona Sarmadi <[email protected]> +--- + mm/mlock.c | 2 ++ + mm/rmap.c | 14 ++++++++++++-- + 2 files changed, 14 insertions(+), 2 deletions(-) + +diff --git a/mm/mlock.c b/mm/mlock.c +index 192e6ee..1b12dfa 100644 +--- a/mm/mlock.c ++++ b/mm/mlock.c +@@ -79,6 +79,7 @@ void clear_page_mlock(struct page *page) + */ + void mlock_vma_page(struct page *page) + { ++ /* Serialize with page migration */ + BUG_ON(!PageLocked(page)); + + if (!TestSetPageMlocked(page)) { +@@ -153,6 +154,7 @@ unsigned int munlock_vma_page(struct page *page) + { + unsigned int nr_pages; + ++ /* For try_to_munlock() and to serialize with page migration */ + BUG_ON(!PageLocked(page)); + + if (TestClearPageMlocked(page)) { +diff --git a/mm/rmap.c b/mm/rmap.c +index b9d2222..6e31398 100644 +--- a/mm/rmap.c ++++ b/mm/rmap.c +@@ -1392,9 +1392,19 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount, + BUG_ON(!page || PageAnon(page)); + + if (locked_vma) { +- mlock_vma_page(page); /* no-op if already mlocked */ +- if (page == check_page) ++ if (page == check_page) { ++ /* we know we have check_page locked */ ++ mlock_vma_page(page); + ret = SWAP_MLOCK; ++ } else if (trylock_page(page)) { ++ /* ++ * If we can lock the page, perform mlock. ++ * Otherwise leave the page alone, it will be ++ * eventually encountered again later. ++ */ ++ mlock_vma_page(page); ++ unlock_page(page); ++ } + continue; /* don't unmap */ + } + +-- +1.9.1 + diff --git a/recipes-kernel/linux/linux-qoriq_3.12.bb b/recipes-kernel/linux/linux-qoriq_3.12.bb index 33bcd37..f078518 100644 --- a/recipes-kernel/linux/linux-qoriq_3.12.bb +++ b/recipes-kernel/linux/linux-qoriq_3.12.bb @@ -33,6 +33,7 @@ SRC_URI = "git://git.freescale.com/ppc/sdk/linux.git;nobranch=1 \ file://target-CVE-2014-4027.patch \ file://fs-isofs-CVE-2014-9420.patch \ file://udp-CVE-2015-5364_CVE-2015-5366.patch \ + file://mm-CVE-2014-3122.patch \ " SRCREV = "6619b8b55796cdf0cec04b66a71288edd3057229" -- 1.9.1 -- _______________________________________________ meta-freescale mailing list [email protected] https://lists.yoctoproject.org/listinfo/meta-freescale
