From: Saeed Mahameed saeedm@nvidia.com
commit 9b29a161ef38040f000dcf9ccf78e34495edfd55 upstream.
In the cited commit, copy_to_user() got called with the wrong pointer, instead of passing the actual buffer ptr to copy from, a pointer to the pointer got passed, which causes a buffer overflow calltrace to pop up when executing "ethtool -x ethX".
Fix ethtool_rxnfc_copy_to_user() to use the rxnfc pointer as passed to the function, instead of a pointer to it.
This fixes below call trace: [ 15.533533] ------------[ cut here ]------------ [ 15.539007] Buffer overflow detected (8 < 192)! [ 15.544110] WARNING: CPU: 3 PID: 1801 at include/linux/thread_info.h:200 copy_overflow+0x15/0x20 [ 15.549308] Modules linked in: [ 15.551449] CPU: 3 PID: 1801 Comm: ethtool Not tainted 5.14.0-rc2+ #1058 [ 15.553919] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014 [ 15.558378] RIP: 0010:copy_overflow+0x15/0x20 [ 15.560648] Code: e9 7c ff ff ff b8 a1 ff ff ff eb c4 66 0f 1f 84 00 00 00 00 00 55 48 89 f2 89 fe 48 c7 c7 88 55 78 8a 48 89 e5 e8 06 5c 1e 00 <0f> 0b 5d c3 0f 1f 80 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41 55 [ 15.565114] RSP: 0018:ffffad49c0523bd0 EFLAGS: 00010286 [ 15.566231] RAX: 0000000000000000 RBX: 00000000000000c0 RCX: 0000000000000000 [ 15.567616] RDX: 0000000000000001 RSI: ffffffff8a7912e7 RDI: 00000000ffffffff [ 15.569050] RBP: ffffad49c0523bd0 R08: ffffffff8ab2ae28 R09: 00000000ffffdfff [ 15.570534] R10: ffffffff8aa4ae40 R11: ffffffff8aa4ae40 R12: 0000000000000000 [ 15.571899] R13: 00007ffd4cc2a230 R14: ffffad49c0523c00 R15: 0000000000000000 [ 15.573584] FS: 00007f538112f740(0000) GS:ffff96d5bdd80000(0000) knlGS:0000000000000000 [ 15.575639] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 15.577092] CR2: 00007f5381226d40 CR3: 0000000013542000 CR4: 00000000001506e0 [ 15.578929] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 15.580695] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 15.582441] Call Trace: [ 15.582970] ethtool_rxnfc_copy_to_user+0x30/0x46 [ 15.583815] ethtool_get_rxnfc.cold+0x23/0x2b [ 15.584584] dev_ethtool+0x29c/0x25f0 [ 15.585286] ? security_netlbl_sid_to_secattr+0x77/0xd0 [ 15.586728] ? do_set_pte+0xc4/0x110 [ 15.587349] ? _raw_spin_unlock+0x18/0x30 [ 15.588118] ? __might_sleep+0x49/0x80 [ 15.588956] dev_ioctl+0x2c1/0x490 [ 15.589616] sock_ioctl+0x18e/0x330 [ 15.591143] __x64_sys_ioctl+0x41c/0x990 [ 15.591823] ? irqentry_exit_to_user_mode+0x9/0x20 [ 15.592657] ? irqentry_exit+0x33/0x40 [ 15.593308] ? exc_page_fault+0x32f/0x770 [ 15.593877] ? exit_to_user_mode_prepare+0x3c/0x130 [ 15.594775] do_syscall_64+0x35/0x80 [ 15.595397] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 15.596037] RIP: 0033:0x7f5381226d4b [ 15.596492] Code: 0f 1e fa 48 8b 05 3d b1 0c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 0d b1 0c 00 f7 d8 64 89 01 48 [ 15.598743] RSP: 002b:00007ffd4cc2a1f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [ 15.599804] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5381226d4b [ 15.600795] RDX: 00007ffd4cc2a350 RSI: 0000000000008946 RDI: 0000000000000003 [ 15.601712] RBP: 00007ffd4cc2a340 R08: 00007ffd4cc2a350 R09: 0000000000000001 [ 15.602751] R10: 00007f538128a990 R11: 0000000000000246 R12: 0000000000000000 [ 15.603882] R13: 00007ffd4cc2a350 R14: 00007ffd4cc2a4b0 R15: 0000000000000000 [ 15.605042] ---[ end trace 325cf185e2795048 ]---
Fixes: dd98d2895de6 ("ethtool: improve compat ioctl handling") Reported-by: Shannon Nelson snelson@pensando.io CC: Arnd Bergmann arnd@arndb.de CC: Christoph Hellwig hch@lst.de Signed-off-by: Saeed Mahameed saeedm@nvidia.com Tested-by: Shannon Nelson snelson@pensando.io Acked-by: Arnd Bergmann arnd@arndb.de Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ethtool/ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/ethtool/ioctl.c +++ b/net/ethtool/ioctl.c @@ -906,7 +906,7 @@ static int ethtool_rxnfc_copy_to_user(vo rule_buf); useraddr += offsetof(struct compat_ethtool_rxnfc, rule_locs); } else { - ret = copy_to_user(useraddr, &rxnfc, size); + ret = copy_to_user(useraddr, rxnfc, size); useraddr += offsetof(struct ethtool_rxnfc, rule_locs); }