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Junling Zheng authored
Based on 08adb7da upstream. Commit 281c9c36 (net: compat: Update get_compat_msghdr() to match copy_msghdr_from_user() behaviour) made get_compat_msghdr() return error if msg_sys->msg_namelen was negative, which changed the behaviors of recvmsg and sendmsg syscall in a lib32 system: Before commit 281c9c36, get_compat_msghdr() wouldn't fail and it would return -EINVAL in move_addr_to_user() or somewhere if msg_sys->msg_namelen was invalid and then syscall returned -EINVAL, which is correct. And now, when msg_sys->msg_namelen is negative, get_compat_msghdr() will fail and wants to return -EINVAL, however, the outer syscall will return -EFAULT directly, which is unexpected. This patch gets the return value of get_compat_msghdr() as well as copy_msghdr_from_user(), then returns this expected value if get_compat_msghdr() fails. Fixes: 281c9c36 (net: compat: Update get_compat_msghdr() to match copy_msghdr_from_user() behaviour) Signed-off-by:
Junling Zheng <zhengjunling@huawei.com> Signed-off-by:
Hanbing Xu <xuhanbing@huawei.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: David Miller <davem@davemloft.net> Signed-off-by:
Luis Henriques <luis.henriques@canonical.com>
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