Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Thomas Gleixner:

 - Expand the space for uncompressing as the LZ4 worst case does not fit
   into the currently reserved space

 - Validate boot parameters more strictly to prevent out of bound access
   in the decompressor/boot code

 - Fix off by one errors in get_segment_base()

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/boot: Prevent faulty bootparams.screeninfo from causing harm
  x86/boot: Provide more slack space during decompression
  x86/ldt: Fix off by one in get_segment_base()
This commit is contained in:
Linus Torvalds 2017-09-03 09:35:21 -07:00
commit d0fa6ea10e
3 changed files with 10 additions and 8 deletions

View file

@ -116,8 +116,7 @@ void __putstr(const char *s)
}
}
if (boot_params->screen_info.orig_video_mode == 0 &&
lines == 0 && cols == 0)
if (lines == 0 || cols == 0)
return;
x = boot_params->screen_info.orig_x;

View file

@ -520,8 +520,14 @@ pref_address: .quad LOAD_PHYSICAL_ADDR # preferred load addr
# the description in lib/decompressor_xxx.c for specific information.
#
# extra_bytes = (uncompressed_size >> 12) + 65536 + 128
#
# LZ4 is even worse: data that cannot be further compressed grows by 0.4%,
# or one byte per 256 bytes. OTOH, we can safely get rid of the +128 as
# the size-dependent part now grows so fast.
#
# extra_bytes = (uncompressed_size >> 8) + 65536
#define ZO_z_extra_bytes ((ZO_z_output_len >> 12) + 65536 + 128)
#define ZO_z_extra_bytes ((ZO_z_output_len >> 8) + 65536)
#if ZO_z_output_len > ZO_z_input_len
# define ZO_z_extract_offset (ZO_z_output_len + ZO_z_extra_bytes - \
ZO_z_input_len)

View file

@ -2335,12 +2335,9 @@ static unsigned long get_segment_base(unsigned int segment)
#ifdef CONFIG_MODIFY_LDT_SYSCALL
struct ldt_struct *ldt;
if (idx > LDT_ENTRIES)
return 0;
/* IRQs are off, so this synchronizes with smp_store_release */
ldt = lockless_dereference(current->active_mm->context.ldt);
if (!ldt || idx > ldt->nr_entries)
if (!ldt || idx >= ldt->nr_entries)
return 0;
desc = &ldt->entries[idx];
@ -2348,7 +2345,7 @@ static unsigned long get_segment_base(unsigned int segment)
return 0;
#endif
} else {
if (idx > GDT_ENTRIES)
if (idx >= GDT_ENTRIES)
return 0;
desc = raw_cpu_ptr(gdt_page.gdt) + idx;