Hi sudip, I am declaring an array of 200 bytes as destination in ioctl processing function itself even i am sending 12 bytes from application. Here is the sample code how i am doing in kernel. ioctl_process(struct iwreq *wrq) { uint8 buffer[200]; copy_from_user(buffer, wrq->u.data.pointer, wrq->u.data.length); //This line itself is causing the problem for me. } Regards, Sateesh. On 07/19/2013 08:26 PM, Sudip Mukherjee wrote: > Hi Santosh > Does your destination buffer have sufficient size to hold the data ? > > Regards > Sudip > > On Fri, Jul 19, 2013 at 7:48 PM, Sateesh Kumar > <sateesh.kumar@xxxxxxxxxxxxxxxxxx> wrote: >> 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, >> Regards, >> Sateesh >> >> >> _______________________________________________ >> Kernelnewbies mailing list >> Kernelnewbies@xxxxxxxxxxxxxxxxx >> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies > -- Regards, Sateesh. _______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies