From 9bfacf249b100d72b2633ac3a43f2c3888e0a41f Mon Sep 17 00:00:00 2001 From: Eugeniu Rosca Date: Sat, 9 Mar 2019 17:27:07 +0100 Subject: [PATCH] core: ofnode: Fix ASAN-reported stack-buffer-overflow in of_get_address v2019.04-rc3 sandbox U-Boot fails to boot when compiled with -fsanitize=address and linked against -lasan, reporting [1]. Git bisecting shows that the issue is contributed by v2019.01 commit 1678754f5e2c ("core: ofnode: Fix ofnode_get_addr_index function"). The root cause seems to be the mismatch between sizeof(u64) and sizeof(fdt_size_t) on sandbox. Luckily, thanks to the fact that the size argument of both of_get_address() and fdtdec_get_addr_size_fixed() is optional, we can pass NULL in its place, avoiding the problem. [1] Backtrace reported by ASAN (gcc 8.1.0): $> ./u-boot -d arch/sandbox/dts/sandbox.dtb [..] Reviewed-by: Simon Glass ================================================================= ==10998==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffcc2331140 at pc 0x0000004eeeb0 bp 0x7ffcc2330f80 sp 0x7ffcc2330f70 WRITE of size 8 at 0x7ffcc2331140 thread T0 #0 0x4eeeaf in of_get_address drivers/core/of_addr.c:154 #1 0x4f7441 in ofnode_get_addr_index drivers/core/ofnode.c:263 #2 0x5b2a78 in sb_eth_ofdata_to_platdata drivers/net/sandbox.c:422 #3 0x4dccd8 in device_probe drivers/core/device.c:407 #4 0x753170 in eth_initialize net/eth-uclass.c:428 #5 0x47d9bf in initr_net common/board_r.c:557 #6 0x6bcfa7 in initcall_run_list lib/initcall.c:30 #7 0x47e1fe in board_init_r common/board_r.c:859 #8 0x4060e5 in main arch/sandbox/cpu/start.c:356 #9 0x7fb8d135482f in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2082f) #10 0x40a3a8 in _start (/path/to/u-boot/u-boot+0x40a3a8) Address 0x7ffcc2331140 is located in stack of thread T0 at offset 32 in frame #0 0x4f72b8 in ofnode_get_addr_index drivers/core/ofnode.c:255 This frame has 3 object(s): [32, 36) 'size' <== Memory access at offset 32 partially overflows this variable [96, 100) 'flags' [160, 168) 'node' HINT: this may be a false positive if your program uses some custom stack unwind mechanism or swapcontext (longjmp and C++ exceptions *are* supported) SUMMARY: AddressSanitizer: stack-buffer-overflow drivers/core/of_addr.c:154 in of_get_address Shadow bytes around the buggy address: 0x10001845e1d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10001845e1e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10001845e1f0: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 0x10001845e200: 04 f2 f2 f2 f2 f2 f2 f2 04 f2 f2 f2 f2 f2 f2 f2 0x10001845e210: 04 f2 f2 f2 f3 f3 f3 f3 00 00 00 00 00 00 00 00 =>0x10001845e220: 00 00 00 00 f1 f1 f1 f1[04]f2 f2 f2 f2 f2 f2 f2 0x10001845e230: 04 f2 f2 f2 f2 f2 f2 f2 00 f2 f2 f2 f3 f3 f3 f3 0x10001845e240: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10001845e250: 00 00 00 00 f1 f1 f1 f1 00 00 f2 f2 f3 f3 f3 f3 0x10001845e260: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 0x10001845e270: f1 f1 00 f2 f2 f2 f3 f3 f3 f3 00 00 00 00 00 00 Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb ==10998==ABORTING 'To' list: git log --since=1year drivers/core/ofnode.c | grep "\-by: .*@" | \ sed 's/.*-by: //' | sort | uniq -c | sort -rn 10 Simon Glass 3 Mario Six 2 Martin Fuzzey 2 Marek Vasut 1 Tom Rini 1 Masahiro Yamada 1 Keerthy 1 Jens Wiklander 1 Bin Meng Fixes: 1678754f5e2c ("core: ofnode: Fix ofnode_get_addr_index function") Signed-off-by: Eugeniu Rosca --- drivers/core/ofnode.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/core/ofnode.c b/drivers/core/ofnode.c index 5a109dd7c9..785f5c3acf 100644 --- a/drivers/core/ofnode.c +++ b/drivers/core/ofnode.c @@ -254,14 +254,13 @@ int ofnode_read_size(ofnode node, const char *propname) fdt_addr_t ofnode_get_addr_index(ofnode node, int index) { int na, ns; - fdt_size_t size; if (ofnode_is_np(node)) { const __be32 *prop_val; uint flags; prop_val = of_get_address(ofnode_to_np(node), index, - (u64 *)&size, &flags); + NULL, &flags); if (!prop_val) return FDT_ADDR_T_NONE; @@ -278,7 +277,7 @@ fdt_addr_t ofnode_get_addr_index(ofnode node, int index) ns = ofnode_read_simple_size_cells(ofnode_get_parent(node)); return fdtdec_get_addr_size_fixed(gd->fdt_blob, ofnode_to_offset(node), "reg", - index, na, ns, &size, true); + index, na, ns, NULL, true); } return FDT_ADDR_T_NONE; -- 2.25.1