On 09.08.2019 16:56, Julia Lawall wrote: > On Fri, 9 Aug 2019, Alexander Popov wrote: >> On 27.03.2019 1:03, Jann Horn wrote: >>> As sparse points out, these two copy_from_user() should actually be >>> copy_to_user(). >> >> I also wrote a coccinelle rule for detecting similar bugs (adding coccinelle >> experts to CC). >> >> >> virtual report >> >> @cfu@ > > You can replace the above line with @cfu exists@. You want to find the > existence of such a call, not ensure that the call occurs on every > control-flow path, which is the default. Thanks Julia, I see `exists` allows to drop `<+ +>`, right? > Do you want this rule to go into the kernel? It turned out that sparse already can find these bugs. Is this rule useful anyway? If so, I can prepare a patch. >> identifier f; >> type t; >> identifier v; >> position decl_p; >> position copy_p; >> @@ >> >> f(..., t v@decl_p, ...) >> { >> <+... >> copy_from_user@copy_p(v, ...) >> ...+> >> } >> >> @script:python@ >> f << cfu.f; >> t << cfu.t; >> v << cfu.v; >> decl_p << cfu.decl_p; >> copy_p << cfu.copy_p; >> @@ >> >> if '__user' in t: >> msg0 = "function \"" + f + "\" has arg \"" + v + "\" of type \"" + t + "\"" >> coccilib.report.print_report(decl_p[0], msg0) >> msg1 = "copy_from_user uses \"" + v + "\" as the destination. What a shame!\n" >> coccilib.report.print_report(copy_p[0], msg1) >> >> >> The rule output: >> >> ./drivers/block/floppy.c:3756:49-52: function "compat_getdrvprm" has arg "arg" >> of type "struct compat_floppy_drive_params __user *" >> ./drivers/block/floppy.c:3783:5-19: copy_from_user uses "arg" as the >> destination. What a shame! >> >> ./drivers/block/floppy.c:3789:49-52: function "compat_getdrvstat" has arg "arg" >> of type "struct compat_floppy_drive_struct __user *" >> ./drivers/block/floppy.c:3819:5-19: copy_from_user uses "arg" as the >> destination. What a shame!