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| author | Mika Westerberg <mika.westerberg@linux.intel.com> | 2020-02-13 12:56:04 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-13 15:59:30 +0300 |
| commit | 03cd45d2e219301880cabc357e3cf478a500080f (patch) | |
| tree | 5f41719fd2686a70664540f47c7a6578eea2a2a1 /drivers | |
| parent | d593126a96b5764116e689e77a66dd1a7823f429 (diff) | |
| download | linux-03cd45d2e219301880cabc357e3cf478a500080f.tar.xz | |
thunderbolt: Prevent crash if non-active NVMem file is read
The driver does not populate .reg_read callback for the non-active NVMem
because the file is supposed to be write-only. However, it turns out
NVMem subsystem does not yet support this and expects that the .reg_read
callback is provided. If user reads the binary attribute it triggers
NULL pointer dereference like this one:
BUG: kernel NULL pointer dereference, address: 0000000000000000
...
Call Trace:
bin_attr_nvmem_read+0x64/0x80
kernfs_fop_read+0xa7/0x180
vfs_read+0xbd/0x170
ksys_read+0x5a/0xd0
do_syscall_64+0x43/0x150
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fix this in the driver by providing .reg_read callback that always
returns an error.
Reported-by: Nicholas Johnson <nicholas.johnson-opensource@outlook.com.au>
Fixes: e6b245ccd524 ("thunderbolt: Add support for host and device NVM firmware upgrade")
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200213095604.1074-1-mika.westerberg@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/thunderbolt/switch.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c index ad5479f21174..7d6ecc342508 100644 --- a/drivers/thunderbolt/switch.c +++ b/drivers/thunderbolt/switch.c @@ -348,6 +348,12 @@ out: return ret; } +static int tb_switch_nvm_no_read(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + return -EPERM; +} + static int tb_switch_nvm_write(void *priv, unsigned int offset, void *val, size_t bytes) { @@ -393,6 +399,7 @@ static struct nvmem_device *register_nvmem(struct tb_switch *sw, int id, config.read_only = true; } else { config.name = "nvm_non_active"; + config.reg_read = tb_switch_nvm_no_read; config.reg_write = tb_switch_nvm_write; config.root_only = true; } |