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authorLinus Torvalds <torvalds@linux-foundation.org>2019-03-24 11:12:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-24 11:12:27 -0700
commit19caf581ba441659f1a71e9a5baed032fdcfceef (patch)
tree5937b0280fa6c5fb9eb67bdf6a0cf1aef364d683 /fs
parenta75eda7bce5e8ffdebe6ddfe513b31e5ec3527d2 (diff)
parentffc8599aa9763f39f6736a79da4d1575e7006f9a (diff)
downloadlinux-stericsson-19caf581ba441659f1a71e9a5baed032fdcfceef.tar.gz
Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner: "A set of x86 fixes: - Prevent potential NULL pointer dereferences in the HPET and HyperV code - Exclude the GART aperture from /proc/kcore to prevent kernel crashes on access - Use the correct macros for Cyrix I/O on Geode processors - Remove yet another kernel address printk leak - Announce microcode reload completion as requested by quite some people. Microcode loading has become popular recently. - Some 'Make Clang' happy fixlets - A few cleanups for recently added code" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/gart: Exclude GART aperture from kcore x86/hw_breakpoints: Make default case in hw_breakpoint_arch_parse() return an error x86/mm/pti: Make local symbols static x86/cpu/cyrix: Remove {get,set}Cx86_old macros used for Cyrix processors x86/cpu/cyrix: Use correct macros for Cyrix calls on Geode processors x86/microcode: Announce reload operation's completion x86/hyperv: Prevent potential NULL pointer dereference x86/hpet: Prevent potential NULL pointer dereference x86/lib: Fix indentation issue, remove extra tab x86/boot: Restrict header scope to make Clang happy x86/mm: Don't leak kernel addresses x86/cpufeature: Fix various quality problems in the <asm/cpu_device_hd.h> header
Diffstat (limited to 'fs')
-rw-r--r--fs/proc/kcore.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index bbcc185062bb..d29d869abec1 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -54,6 +54,28 @@ static LIST_HEAD(kclist_head);
static DECLARE_RWSEM(kclist_lock);
static int kcore_need_update = 1;
+/*
+ * Returns > 0 for RAM pages, 0 for non-RAM pages, < 0 on error
+ * Same as oldmem_pfn_is_ram in vmcore
+ */
+static int (*mem_pfn_is_ram)(unsigned long pfn);
+
+int __init register_mem_pfn_is_ram(int (*fn)(unsigned long pfn))
+{
+ if (mem_pfn_is_ram)
+ return -EBUSY;
+ mem_pfn_is_ram = fn;
+ return 0;
+}
+
+static int pfn_is_ram(unsigned long pfn)
+{
+ if (mem_pfn_is_ram)
+ return mem_pfn_is_ram(pfn);
+ else
+ return 1;
+}
+
/* This doesn't grab kclist_lock, so it should only be used at init time. */
void __init kclist_add(struct kcore_list *new, void *addr, size_t size,
int type)
@@ -465,6 +487,11 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
goto out;
}
m = NULL; /* skip the list anchor */
+ } else if (!pfn_is_ram(__pa(start) >> PAGE_SHIFT)) {
+ if (clear_user(buffer, tsz)) {
+ ret = -EFAULT;
+ goto out;
+ }
} else if (m->type == KCORE_VMALLOC) {
vread(buf, (char *)start, tsz);
/* we have to zero-fill user buffer even if no read */