| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 08/78] qlge: avoid memcpy buffer overflow | Date | Mon, 18 Sep 2017 11:11:17 +0200 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Arnd Bergmann <arnd@arndb.de>
[ Upstream commit e58f95831e7468d25eb6e41f234842ecfe6f014f ]
gcc-8.0.0 (snapshot) points out that we copy a variable-length string into a fixed length field using memcpy() with the destination length, and that ends up copying whatever follows the string:
inlined from 'ql_core_dump' at drivers/net/ethernet/qlogic/qlge/qlge_dbg.c:1106:2: drivers/net/ethernet/qlogic/qlge/qlge_dbg.c:708:2: error: 'memcpy' reading 15 bytes from a region of size 14 [-Werror=stringop-overflow=] memcpy(seg_hdr->description, desc, (sizeof(seg_hdr->description)) - 1);
Changing it to use strncpy() will instead zero-pad the destination, which seems to be the right thing to do here.
The bug is probably harmless, but it seems like a good idea to address it in stable kernels as well, if only for the purpose of building with gcc-8 without warnings.
Fixes: a61f80261306 ("qlge: Add ethtool register dump function.") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/net/ethernet/qlogic/qlge/qlge_dbg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/net/ethernet/qlogic/qlge/qlge_dbg.c +++ b/drivers/net/ethernet/qlogic/qlge/qlge_dbg.c @@ -724,7 +724,7 @@ static void ql_build_coredump_seg_header seg_hdr->cookie = MPI_COREDUMP_COOKIE; seg_hdr->segNum = seg_number; seg_hdr->segSize = seg_size; - memcpy(seg_hdr->description, desc, (sizeof(seg_hdr->description)) - 1); + strncpy(seg_hdr->description, desc, (sizeof(seg_hdr->description)) - 1); } /*
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