diff options
| author | Linn Crosetto <linn@hp.com> | 2013-08-13 15:46:41 -0600 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2013-08-13 23:29:19 -0700 |
| commit | 30e46b574a1db7d14404e52dca8e1aa5f5155fd2 (patch) | |
| tree | 830c013b0e1bc37b77590df2998e664c89974571 | |
| parent | 2449f343e4adc778de1c3d45b5aa14fe788663f5 (diff) | |
| download | op-kernel-dev-30e46b574a1db7d14404e52dca8e1aa5f5155fd2.zip op-kernel-dev-30e46b574a1db7d14404e52dca8e1aa5f5155fd2.tar.gz | |
x86: avoid remapping data in parse_setup_data()
Type SETUP_PCI, added by setup_efi_pci(), may advertise a ROM size
larger than early_memremap() is able to handle, which is currently
limited to 256kB. If this occurs it leads to a NULL dereference in
parse_setup_data().
To avoid this, remap the setup_data header and allow parsing functions
for individual types to handle their own data remapping.
Signed-off-by: Linn Crosetto <linn@hp.com>
Link: http://lkml.kernel.org/r/1376430401-67445-1-git-send-email-linn@hp.com
Acked-by: Yinghai Lu <yinghai@kernel.org>
Reviewed-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
| -rw-r--r-- | arch/x86/include/asm/e820.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/e820.c | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/setup.c | 19 |
3 files changed, 13 insertions, 13 deletions
diff --git a/arch/x86/include/asm/e820.h b/arch/x86/include/asm/e820.h index cccd07f..779c2ef 100644 --- a/arch/x86/include/asm/e820.h +++ b/arch/x86/include/asm/e820.h @@ -29,7 +29,7 @@ extern void e820_setup_gap(void); extern int e820_search_gap(unsigned long *gapstart, unsigned long *gapsize, unsigned long start_addr, unsigned long long end_addr); struct setup_data; -extern void parse_e820_ext(struct setup_data *data); +extern void parse_e820_ext(u64 phys_addr, u32 data_len); #if defined(CONFIG_X86_64) || \ (defined(CONFIG_X86_32) && defined(CONFIG_HIBERNATION)) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index d32abea..174da5f 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -658,15 +658,18 @@ __init void e820_setup_gap(void) * boot_params.e820_map, others are passed via SETUP_E820_EXT node of * linked list of struct setup_data, which is parsed here. */ -void __init parse_e820_ext(struct setup_data *sdata) +void __init parse_e820_ext(u64 phys_addr, u32 data_len) { int entries; struct e820entry *extmap; + struct setup_data *sdata; + sdata = early_memremap(phys_addr, data_len); entries = sdata->len / sizeof(struct e820entry); extmap = (struct e820entry *)(sdata->data); __append_e820_map(extmap, entries); sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); + early_iounmap(sdata, data_len); printk(KERN_INFO "e820: extended physical RAM map:\n"); e820_print_map("extended"); } diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c index de33798..b6b45e4 100644 --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -426,25 +426,23 @@ static void __init reserve_initrd(void) static void __init parse_setup_data(void) { struct setup_data *data; - u64 pa_data; + u64 pa_data, pa_next; pa_data = boot_params.hdr.setup_data; while (pa_data) { - u32 data_len, map_len; + u32 data_len, map_len, data_type; map_len = max(PAGE_SIZE - (pa_data & ~PAGE_MASK), (u64)sizeof(struct setup_data)); data = early_memremap(pa_data, map_len); data_len = data->len + sizeof(struct setup_data); - if (data_len > map_len) { - early_iounmap(data, map_len); - data = early_memremap(pa_data, data_len); - map_len = data_len; - } + data_type = data->type; + pa_next = data->next; + early_iounmap(data, map_len); - switch (data->type) { + switch (data_type) { case SETUP_E820_EXT: - parse_e820_ext(data); + parse_e820_ext(pa_data, data_len); break; case SETUP_DTB: add_dtb(pa_data); @@ -452,8 +450,7 @@ static void __init parse_setup_data(void) default: break; } - pa_data = data->next; - early_iounmap(data, map_len); + pa_data = pa_next; } } |
