qedf driver, debugfs part of it specifically, touches __user pointers
directly for printing out info to userspace via sprintf(), which may
cause crash like this:
BUG: unable to handle kernel paging request at 00007ffd1d6b43a0
IP: [<ffffffffaa7a882a>] string.isra.7+0x6a/0xf0
Oops: 0003 [#1] SMP
Call Trace:
[<ffffffffaa7a9f31>] vsnprintf+0x201/0x6a0
[<ffffffffaa7aa556>] sprintf+0x56/0x80
[<ffffffffc04227ed>] qedf_dbg_stop_io_on_error_cmd_read+0x6d/0x90 [qedf]
[<ffffffffaa65bb2f>] vfs_read+0x9f/0x170
[<ffffffffaa65cb82>] SyS_pread64+0x92/0xc0
Avoid this by preparing the info in a kernel buffer first, either
allocated on stack for small printouts, or via vmalloc() for big ones,
and then copying it to the userspace properly.
Changes since v1 [1]:
* use scnprintf() for on-stack buffers too
* adjust an on-stack buffer size in qedf_dbg_debug_cmd_read() to be a
multiple of 8, and also size it properly
* accumulate acks and reviews
[1] https://lore.kernel.org/lkml/20230728065819.139694-1-oleksandr@xxxxxxxxxx/
Oleksandr Natalenko (3):
scsi: qedf: do not touch __user pointer in
qedf_dbg_stop_io_on_error_cmd_read() directly
scsi: qedf: do not touch __user pointer in qedf_dbg_debug_cmd_read()
directly
scsi: qedf: do not touch __user pointer in qedf_dbg_fp_int_cmd_read()
directly
drivers/scsi/qedf/qedf_dbg.h | 2 ++
drivers/scsi/qedf/qedf_debugfs.c | 35 +++++++++++++++++++-------------
2 files changed, 23 insertions(+), 14 deletions(-)
--
2.41.0
