Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1717735

[PATCH 4.12 19/41] mm/cma_debug.c: fix stack corruption due to sprintf usage

Show all headers | View raw

4.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Prakash Gupta <guptap@codeaurora.org>

commit da094e42848e3c36feaa3b5271e53983fd45424f upstream.

name[] in cma_debugfs_add_one() can only accommodate 16 chars including
NULL to store sprintf output.  It's common for cma device name to be
larger than 15 chars.  This can cause stack corrpution.  If the gcc
stack protector is turned on, this can cause a panic due to stack
corruption.

Below is one example trace:

  Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in:
  ffffff8e69a75730
  Call trace:
     dump_backtrace+0x0/0x2c4
     show_stack+0x20/0x28
     dump_stack+0xb8/0xf4
     panic+0x154/0x2b0
     print_tainted+0x0/0xc0
     cma_debugfs_init+0x274/0x290
     do_one_initcall+0x5c/0x168
     kernel_init_freeable+0x1c8/0x280

Fix the short sprintf buffer in cma_debugfs_add_one() by using
scnprintf() instead of sprintf().

Link: http://lkml.kernel.org/r/1502446217-21840-1-git-send-email-guptap@codeaurora.org
Fixes: f318dd083c81 ("cma: Store a name in the cma structure")
Signed-off-by: Prakash Gupta <guptap@codeaurora.org>
Acked-by: Laura Abbott <labbott@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 mm/cma_debug.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/cma_debug.c
+++ b/mm/cma_debug.c
@@ -167,7 +167,7 @@ static void cma_debugfs_add_one(struct c
 	char name[16];
 	int u32s;
 
-	sprintf(name, "cma-%s", cma->name);
+	scnprintf(name, sizeof(name), "cma-%s", cma->name);
 
 	tmp = debugfs_create_dir(name, cma_debugfs_root);
 

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH 4.12 00/41] 4.12.9-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 28/41] perf/x86: Fix RDPMC vs. mm_struct tracking Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 09/41] md: fix test in md_write_start() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 31/41] x86/elf: Remove the unnecessary ADDR_NO_RANDOMIZE checks Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 19/41] mm/cma_debug.c: fix stack corruption due to sprintf usage Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 21/41] mm/vmalloc.c: dont unconditonally use __GFP_HIGHMEM Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 02/41] parisc: pci memory bar assignment fails with 64bit kernels on dino/cujo Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 10/41] md: always clear ->safemode when md_check_recovery gets the mddev lock. Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 25/41] blk-mq-pci: add a fallback when pci_irq_get_affinity returns NULL Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 05/41] drm/i915: Perform an invalidate prior to executing golden renderstate Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 22/41] mm: revert x86_64 and arm64 ELF_ET_DYN_BASE base changes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 01/41] audit: Fix use after free in audit_remove_watch_rule() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 27/41] xen-blkfront: use a right index when checking requests Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 18/41] mm: fix double mmap_sem unlock on MMF_UNSTABLE enforced SIGBUS Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 32/41] irqchip/atmel-aic: Fix unbalanced of_node_put() in aic_common_irq_fixup() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  [PATCH 4.12 29/41] x86/asm/64: Clear AC on NMI entries Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-22 21:30 +0200
  Re: [PATCH 4.12 00/41] 4.12.9-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2017-08-23 02:40 +0200
    Re: [PATCH 4.12 00/41] 4.12.9-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-08-23 02:50 +0200

csiph-web