From df1ce63447eab99baa0ded47ccde357863c2d976 Mon Sep 17 00:00:00 2001 From: Philipp Rudo Date: Mon, 13 Aug 2018 11:16:57 +0200 Subject: [PATCH] s390/kdump: Fix memleak in nt_vmcoreinfo [ Upstream commit 2d2e7075b87181ed0c675e4936e20bdadba02e1f ] The vmcoreinfo of a crashed system is potentially fragmented. Thus the crash kernel has an intermediate step where the vmcoreinfo is copied into a temporary, continuous buffer in the crash kernel memory. This temporary buffer is never freed. Free it now to prevent the memleak. While at it replace all occurrences of "VMCOREINFO" by its corresponding macro to prevent potential renaming issues. Signed-off-by: Philipp Rudo Acked-by: Heiko Carstens Signed-off-by: Heiko Carstens Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/crash_dump.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c index 9f5ea9d87069..9b0216d571ad 100644 --- a/arch/s390/kernel/crash_dump.c +++ b/arch/s390/kernel/crash_dump.c @@ -404,11 +404,13 @@ static void *get_vmcoreinfo_old(unsigned long *size) if (copy_oldmem_kernel(nt_name, addr + sizeof(note), sizeof(nt_name) - 1)) return NULL; - if (strcmp(nt_name, "VMCOREINFO") != 0) + if (strcmp(nt_name, VMCOREINFO_NOTE_NAME) != 0) return NULL; vmcoreinfo = kzalloc_panic(note.n_descsz); - if (copy_oldmem_kernel(vmcoreinfo, addr + 24, note.n_descsz)) + if (copy_oldmem_kernel(vmcoreinfo, addr + 24, note.n_descsz)) { + kfree(vmcoreinfo); return NULL; + } *size = note.n_descsz; return vmcoreinfo; } @@ -418,15 +420,20 @@ static void *get_vmcoreinfo_old(unsigned long *size) */ static void *nt_vmcoreinfo(void *ptr) { + const char *name = VMCOREINFO_NOTE_NAME; unsigned long size; void *vmcoreinfo; vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size); - if (!vmcoreinfo) - vmcoreinfo = get_vmcoreinfo_old(&size); + if (vmcoreinfo) + return nt_init_name(ptr, 0, vmcoreinfo, size, name); + + vmcoreinfo = get_vmcoreinfo_old(&size); if (!vmcoreinfo) return ptr; - return nt_init_name(ptr, 0, vmcoreinfo, size, "VMCOREINFO"); + ptr = nt_init_name(ptr, 0, vmcoreinfo, size, name); + kfree(vmcoreinfo); + return ptr; } /*