diff options
Diffstat (limited to 'common/recipes-kernel/linux/linux-yocto-4.9.21/0079-x86-kexec-Avoid-double-free_page-upon-do_kexec_load-.patch')
| -rw-r--r-- | common/recipes-kernel/linux/linux-yocto-4.9.21/0079-x86-kexec-Avoid-double-free_page-upon-do_kexec_load-.patch | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/common/recipes-kernel/linux/linux-yocto-4.9.21/0079-x86-kexec-Avoid-double-free_page-upon-do_kexec_load-.patch b/common/recipes-kernel/linux/linux-yocto-4.9.21/0079-x86-kexec-Avoid-double-free_page-upon-do_kexec_load-.patch new file mode 100644 index 00000000..b3f12503 --- /dev/null +++ b/common/recipes-kernel/linux/linux-yocto-4.9.21/0079-x86-kexec-Avoid-double-free_page-upon-do_kexec_load-.patch @@ -0,0 +1,106 @@ +From f4e4c29205e3747d4cc2d033e1c46ad9725e9886 Mon Sep 17 00:00:00 2001 +From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> +Date: Wed, 9 May 2018 19:42:20 +0900 +Subject: [PATCH 79/93] x86/kexec: Avoid double free_page() upon + do_kexec_load() failure + +commit a466ef76b815b86748d9870ef2a430af7b39c710 upstream. + +>From ff82bedd3e12f0d3353282054ae48c3bd8c72012 Mon Sep 17 00:00:00 2001 +From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> +Date: Wed, 9 May 2018 12:12:39 +0900 +Subject: x86/kexec: Avoid double free_page() upon do_kexec_load() failure + +syzbot is reporting crashes after memory allocation failure inside +do_kexec_load() [1]. This is because free_transition_pgtable() is called +by both init_transition_pgtable() and machine_kexec_cleanup() when memory +allocation failed inside init_transition_pgtable(). + +Regarding 32bit code, machine_kexec_free_page_tables() is called by both +machine_kexec_alloc_page_tables() and machine_kexec_cleanup() when memory +allocation failed inside machine_kexec_alloc_page_tables(). + +Fix this by leaving the error handling to machine_kexec_cleanup() +(and optionally setting NULL after free_page()). + +[1] https://syzkaller.appspot.com/bug?id=91e52396168cf2bdd572fe1e1bc0bc645c1c6b40 + +Fixes: f5deb79679af6eb4 ("x86: kexec: Use one page table in x86_64 machine_kexec") +Fixes: 92be3d6bdf2cb349 ("kexec/i386: allocate page table pages dynamically") +Reported-by: syzbot <syzbot+d96f60296ef613fe1d69@syzkaller.appspotmail.com> +Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Acked-by: Baoquan He <bhe@redhat.com> +Cc: thomas.lendacky@amd.com +Cc: prudo@linux.vnet.ibm.com +Cc: Huang Ying <ying.huang@intel.com> +Cc: syzkaller-bugs@googlegroups.com +Cc: takahiro.akashi@linaro.org +Cc: H. Peter Anvin <hpa@zytor.com> +Cc: akpm@linux-foundation.org +Cc: dyoung@redhat.com +Cc: kirill.shutemov@linux.intel.com +Link: https://lkml.kernel.org/r/201805091942.DGG12448.tMFVFSJFQOOLHO@I-love.SAKURA.ne.jp +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +--- + arch/x86/kernel/machine_kexec_32.c | 6 +++++- + arch/x86/kernel/machine_kexec_64.c | 4 +++- + 2 files changed, 8 insertions(+), 2 deletions(-) + +diff --git a/arch/x86/kernel/machine_kexec_32.c b/arch/x86/kernel/machine_kexec_32.c +index 469b23d..fd7e993 100644 +--- a/arch/x86/kernel/machine_kexec_32.c ++++ b/arch/x86/kernel/machine_kexec_32.c +@@ -71,12 +71,17 @@ static void load_segments(void) + static void machine_kexec_free_page_tables(struct kimage *image) + { + free_page((unsigned long)image->arch.pgd); ++ image->arch.pgd = NULL; + #ifdef CONFIG_X86_PAE + free_page((unsigned long)image->arch.pmd0); ++ image->arch.pmd0 = NULL; + free_page((unsigned long)image->arch.pmd1); ++ image->arch.pmd1 = NULL; + #endif + free_page((unsigned long)image->arch.pte0); ++ image->arch.pte0 = NULL; + free_page((unsigned long)image->arch.pte1); ++ image->arch.pte1 = NULL; + } + + static int machine_kexec_alloc_page_tables(struct kimage *image) +@@ -93,7 +98,6 @@ static int machine_kexec_alloc_page_tables(struct kimage *image) + !image->arch.pmd0 || !image->arch.pmd1 || + #endif + !image->arch.pte0 || !image->arch.pte1) { +- machine_kexec_free_page_tables(image); + return -ENOMEM; + } + return 0; +diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c +index 8c1f218..26242cd 100644 +--- a/arch/x86/kernel/machine_kexec_64.c ++++ b/arch/x86/kernel/machine_kexec_64.c +@@ -37,8 +37,11 @@ static struct kexec_file_ops *kexec_file_loaders[] = { + static void free_transition_pgtable(struct kimage *image) + { + free_page((unsigned long)image->arch.pud); ++ image->arch.pud = NULL; + free_page((unsigned long)image->arch.pmd); ++ image->arch.pmd = NULL; + free_page((unsigned long)image->arch.pte); ++ image->arch.pte = NULL; + } + + static int init_transition_pgtable(struct kimage *image, pgd_t *pgd) +@@ -79,7 +82,6 @@ static int init_transition_pgtable(struct kimage *image, pgd_t *pgd) + set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC)); + return 0; + err: +- free_transition_pgtable(image); + return result; + } + +-- +2.7.4 + |