4.18-stable review patch. If anyone has any objections, please let me know.
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From: Philipp Rudo prudo@linux.ibm.com
[ 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 prudo@linux.ibm.com Acked-by: Heiko Carstens heiko.carstens@de.ibm.com Signed-off-by: Heiko Carstens heiko.carstens@de.ibm.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/s390/kernel/crash_dump.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)
--- a/arch/s390/kernel/crash_dump.c +++ b/arch/s390/kernel/crash_dump.c @@ -404,11 +404,13 @@ static void *get_vmcoreinfo_old(unsigned 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 */ 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; }
/*