tag df1c2cb160e8162653ac2fb58c51c05b75fbe6ac
tagger Bjorn Helgaas <bhelgaas@google.com> Fri Oct 15 14:32:06 2021 -0500
object 2b94b6b79b7c24092a6169db9e83c4565be0db42

pci-v5.15-fixes-2

commit 2b94b6b79b7c24092a6169db9e83c4565be0db42
author Wang Hai <wanghai38@huawei.com> Tue Oct 12 15:15:56 2021 +0800
committer Bjorn Helgaas <bhelgaas@google.com> Tue Oct 12 20:32:58 2021 -0500
tree c126bd628459100d0bd82f29d6954058db5bada3
parent e4e737bb5c170df6135a127739a9e6148ee3da82

PCI/MSI: Handle msi_populate_sysfs() errors correctly

Previously, when msi_populate_sysfs() failed, we saved the error return
value as dev->msi_irq_groups, which leads to a page fault when
free_msi_irqs() calls msi_destroy_sysfs().

To prevent this, leave dev->msi_irq_groups alone when msi_populate_sysfs()
fails.

Found by the Hulk Robot when injecting a memory allocation fault in
msi_populate_sysfs():

  BUG: unable to handle page fault for address: fffffffffffffff4
  ...
  Call Trace:
   msi_destroy_sysfs+0x30/0xa0
   free_msi_irqs+0x11d/0x1b0

Fixes: 2f170814bdd2 ("genirq/msi: Move MSI sysfs handling from PCI to MSI core")
Link: https://lore.kernel.org/r/20211012071556.939137-1-wanghai38@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Barry Song <song.bao.hua@hisilicon.com>