You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
85 lines
3.4 KiB
85 lines
3.4 KiB
From 548e9b916f86c06e2cdb50d8f49633f9bec66c7e Mon Sep 17 00:00:00 2001 |
|
From: Logan Gunthorpe <logang@deltatee.com> |
|
Date: Wed, 22 Jun 2022 14:25:09 -0600 |
|
Subject: [PATCH 34/52] mdadm/Grow: Fix use after close bug by closing after |
|
fork |
|
|
|
The test 07reshape-grow fails most of the time. But it succeeds around |
|
1 in 5 times. When it does succeed, it causes the tests to die because |
|
mdadm has segfaulted. |
|
|
|
The segfault was caused by mdadm attempting to repoen a file |
|
descriptor that was already closed. The backtrace of the segfault |
|
was: |
|
|
|
#0 __strncmp_avx2 () at ../sysdeps/x86_64/multiarch/strcmp-avx2.S:101 |
|
#1 0x000056146e31d44b in devnm2devid (devnm=0x0) at util.c:956 |
|
#2 0x000056146e31dab4 in open_dev_flags (devnm=0x0, flags=0) |
|
at util.c:1072 |
|
#3 0x000056146e31db22 in open_dev (devnm=0x0) at util.c:1079 |
|
#4 0x000056146e3202e8 in reopen_mddev (mdfd=4) at util.c:2244 |
|
#5 0x000056146e329f36 in start_array (mdfd=4, |
|
mddev=0x7ffc55342450 "/dev/md0", content=0x7ffc55342860, |
|
st=0x56146fc78660, ident=0x7ffc55342f70, best=0x56146fc6f5d0, |
|
bestcnt=10, chosen_drive=0, devices=0x56146fc706b0, okcnt=5, |
|
sparecnt=0, rebuilding_cnt=0, journalcnt=0, c=0x7ffc55342e90, |
|
clean=1, avail=0x56146fc78720 "\001\001\001\001\001", |
|
start_partial_ok=0, err_ok=0, was_forced=0) |
|
at Assemble.c:1206 |
|
#6 0x000056146e32c36e in Assemble (st=0x56146fc78660, |
|
mddev=0x7ffc55342450 "/dev/md0", ident=0x7ffc55342f70, |
|
devlist=0x56146fc6e2d0, c=0x7ffc55342e90) |
|
at Assemble.c:1914 |
|
#7 0x000056146e312ac9 in main (argc=11, argv=0x7ffc55343238) |
|
at mdadm.c:1510 |
|
|
|
The file descriptor was closed early in Grow_continue(). The noted commit |
|
moved the close() call to close the fd above the fork which caused the |
|
parent process to return with a closed fd. |
|
|
|
This meant reshape_array() and Grow_continue() would return in the parent |
|
with the fd forked. The fd would eventually be passed to reopen_mddev() |
|
which returned an unhandled NULL from fd2devnm() which would then be |
|
dereferenced in devnm2devid. |
|
|
|
Fix this by moving the close() call below the fork. This appears to |
|
fix the 07revert-grow test. While we're at it, switch to using |
|
close_fd() to invalidate the file descriptor. |
|
|
|
Fixes: 77b72fa82813 ("mdadm/Grow: prevent md's fd from being occupied during delayed time") |
|
Cc: Alex Wu <alexwu@synology.com> |
|
Cc: BingJing Chang <bingjingc@synology.com> |
|
Cc: Danny Shih <dannyshih@synology.com> |
|
Cc: ChangSyun Peng <allenpeng@synology.com> |
|
Signed-off-by: Logan Gunthorpe <logang@deltatee.com> |
|
Acked-by: Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com> |
|
Signed-off-by: Jes Sorensen <jes@trained-monkey.org> |
|
--- |
|
Grow.c | 4 +++- |
|
1 file changed, 3 insertions(+), 1 deletion(-) |
|
|
|
diff --git a/Grow.c b/Grow.c |
|
index 8c520d42..97f22c75 100644 |
|
--- a/Grow.c |
|
+++ b/Grow.c |
|
@@ -3514,7 +3514,6 @@ started: |
|
return 0; |
|
} |
|
|
|
- close(fd); |
|
/* Now we just need to kick off the reshape and watch, while |
|
* handling backups of the data... |
|
* This is all done by a forked background process. |
|
@@ -3535,6 +3534,9 @@ started: |
|
break; |
|
} |
|
|
|
+ /* Close unused file descriptor in the forked process */ |
|
+ close_fd(&fd); |
|
+ |
|
/* If another array on the same devices is busy, the |
|
* reshape will wait for them. This would mean that |
|
* the first section that we suspend will stay suspended |
|
-- |
|
2.31.1 |
|
|
|
|