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Mika Westerberg
03cd45d2e2
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 <[email protected]>
Fixes: e6b245ccd5 ("thunderbolt: Add support for host and device NVM firmware upgrade")
Signed-off-by: Mika Westerberg <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>