https://github.com/torvalds/linux
Revision 0ee4e76937d69128a6a66861ba393ebdc2ffc8a2 authored by Vivien Didelot on 03 June 2019, 20:57:13 UTC, committed by David S. Miller on 06 June 2019, 00:15:27 UTC
ethtool_get_regs() allocates a buffer of size ops->get_regs_len(), and pass it to the kernel driver via ops->get_regs() for filling. There is no restriction about what the kernel drivers can or cannot do with the open ethtool_regs structure. They usually set regs->version and ignore regs->len or set it to the same size as ops->get_regs_len(). But if userspace allocates a smaller buffer for the registers dump, we would cause a userspace buffer overflow in the final copy_to_user() call, which uses the regs.len value potentially reset by the driver. To fix this, make this case obvious and store regs.len before calling ops->get_regs(), to only copy as much data as requested by userspace, up to the value returned by ops->get_regs_len(). While at it, remove the redundant check for non-null regbuf. Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com> Reviewed-by: Michal Kubecek <mkubecek@suse.cz> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 0a8dd9f
Tip revision: 0ee4e76937d69128a6a66861ba393ebdc2ffc8a2 authored by Vivien Didelot on 03 June 2019, 20:57:13 UTC
ethtool: fix potential userspace buffer overflow
ethtool: fix potential userspace buffer overflow
Tip revision: 0ee4e76
| File | Mode | Size |
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | -rw-r--r-- | 14.6 KB |
| .cocciconfig | -rw-r--r-- | 59 bytes |
| .get_maintainer.ignore | -rw-r--r-- | 71 bytes |
| .gitattributes | -rw-r--r-- | 30 bytes |
| .gitignore | -rw-r--r-- | 1.6 KB |
| .mailmap | -rw-r--r-- | 11.9 KB |
| COPYING | -rw-r--r-- | 423 bytes |
| CREDITS | -rw-r--r-- | 96.9 KB |
| Kbuild | -rw-r--r-- | 1.5 KB |
| Kconfig | -rw-r--r-- | 563 bytes |
| MAINTAINERS | -rw-r--r-- | 498.9 KB |
| Makefile | -rw-r--r-- | 58.8 KB |
| README | -rw-r--r-- | 727 bytes |
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