Issue with copy_from_user() function in kernel 3.6.10

Sateesh Kumar sateesh.kumar at
Fri Jul 19 10:18:50 EDT 2013

Dear Experts,

I am using the kernel 3.6.10 for my driver development. When I compiled 
the code I am getting the following warning. I am facing the same issue 
with 3.5.4 kernel.

"call to ‘copy_from_user_overflow’ declared with attribute warning: 
copy_from_user() buffer size is not provably correct"

When I try to install the module, I am facing the kernel crash. Here is 
the crash log.

//Kernel crash log - Start

Call Trace:
[19592.491229] [<c044bbf2>] warn_slowpath_common+0x72/0xa0
[19592.491233] [<c06882b7>] ? copy_from_user_overflow+0x27/0x30
[19592.491236] [<c06882b7>] ? copy_from_user_overflow+0x27/0x30
[19592.491241] [<f86f54c0>] ? jtag_usb_card_read+0x70/0x70 [usb_jtag]
[19592.491244] [<c044bcc3>] warn_slowpath_fmt+0x33/0x40
[19592.491247] [<c06882b7>] copy_from_user_overflow+0x27/0x30
[19592.491251] [<f86f54ec>] jtag_usb_ioctl+0x2c/0x80 [usb_jtag]
[19592.491256] [<c0565dea>] do_vfs_ioctl+0x7a/0x590
[19592.491259] [<c055f41b>] ? putname+0x2b/0x40
[19592.491262] [<c055f41b>] ? putname+0x2b/0x40
[19592.491265] [<c0555238>] ? do_sys_open+0x158/0x1c0
[19592.491269] [<c0566368>] sys_ioctl+0x68/0x80
[19592.491274] [<c0980cdf>] sysenter_do_call+0x12/0x28
[19592.491276] ---[ end trace 98bdb358664246ac ]---
[19592.491277] copy_from_usr error

//Kernel crash log - End

Please let me know, what wrong with my driver?

Thanks in advance,

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