Messages in this thread | | | Date | Fri, 8 Jul 2011 13:30:56 +0300 | Subject | Re: [PATCH 1/3] uml: drivers/net_user.c memory leak fix | From | Vitaliy Ivanov <> |
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On Thu, Jul 7, 2011 at 8:27 PM, Richard Weinberger <richard@nod.at> wrote: > Am Donnerstag 07 Juli 2011, 18:36:02 schrieb Vitaliy Ivanov: >> >From 9b9f36f46aa708c3245f5ded83f96421966b2edf Mon Sep 17 00:00:00 2001 >> >> From: Vitaliy Ivanov <vitalivanov@gmail.com> >> Date: Thu, 7 Jul 2011 19:23:13 +0300 >> Subject: [PATCH 1/3] uml: drivers/net_user.c memory leak fix >> >> Perform memory cleanup on exit. >> On receiving invalid 'pid' we still should clean 'output' variable. >> >> Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com> >> --- >> arch/um/drivers/net_user.c | 5 +++-- >> 1 files changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/arch/um/drivers/net_user.c b/arch/um/drivers/net_user.c >> index 9415dd9..989b653 100644 >> --- a/arch/um/drivers/net_user.c >> +++ b/arch/um/drivers/net_user.c >> @@ -228,10 +228,11 @@ static void change(char *dev, char *what, unsigned >> char *addr, "buffer\n"); >> >> pid = change_tramp(argv, output, output_len); >> - if (pid < 0) return; >> >> if (output != NULL) { >> - printk("%s", output); >> + if (pid >= 0) { >> + printk("%s", output); >> + } >> kfree(output); >> } >> } > > This control logic is a bit strange. > When change_tramp() fails we should not printk() the output variable. > > if (pid < 0){ > free(output); > return; > } > > Would be much cleaner.
I just didn't want to clone this free-return stuff. So, what you proposing is like this: ------------ ... output = uml_kmalloc(output_len, UM_GFP_KERNEL); if (output == NULL) printk(UM_KERN_ERR "change : failed to allocate output " "buffer\n");
pid = change_tramp(argv, output, output_len); if (pid < 0) { free(output); <---------- I'm not sure but 'output' can be NULL here. return; }
if (output != NULL) { printk("%s", output); kfree(output); } } ------------
I was trying to print 'output' only in case change_tramp is successful. That's the old logic. And at the same time perform free only in case output is not NULL.
Vitaliy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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