| Message ID | 20240206191125.13065-1-jgross@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] Mini-OS: fix 9pfs frontend error path | expand |
Juergen Gross, le mar. 06 févr. 2024 20:11:25 +0100, a ecrit: > The early error exit in p9_stat() returns without zeroing the p9_stat > buffer, resulting in free() being called with an uninitialized pointer. > > Fix that by calling free_stat() in p9_stat() in case of returning an > error and potentially having allocated strings. > > Reported-by: Julien Grall <julien@xen.org> > Fixes: 2d1dfccd3aa3 ("Mini-OS: add read and write support to 9pfsfront") > Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org> Thanks! > --- > V2: > - call free_stat() in p9_stat() in case of returning an error > (Samuel Thibault) > --- > 9pfront.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/9pfront.c b/9pfront.c > index 315089bc..042879a7 100644 > --- a/9pfront.c > +++ b/9pfront.c > @@ -728,6 +728,8 @@ static int p9_stat(struct dev_9pfs *dev, uint32_t fid, struct p9_stat *stat) > &stat->extension, &stat->n_uid, &stat->n_gid, &stat->n_muid); > > ret = req->result; > + if ( ret ) > + free_stat(&stat); > > put_free_req(dev, req); > > @@ -932,13 +934,13 @@ static int write_9pfs(struct file *file, const void *buf, size_t nbytes) > if ( f9pfs->append ) > { > ret = p9_stat(f9pfs->dev, f9pfs->fid, &stat); > - free_stat(&stat); > if ( ret ) > { > errno = EIO; > return -1; > } > file->offset = stat.length; > + free_stat(&stat); > } > > ret = p9_write(f9pfs->dev, f9pfs->fid, file->offset, buf, nbytes); > -- > 2.35.3
diff --git a/9pfront.c b/9pfront.c index 315089bc..042879a7 100644 --- a/9pfront.c +++ b/9pfront.c @@ -728,6 +728,8 @@ static int p9_stat(struct dev_9pfs *dev, uint32_t fid, struct p9_stat *stat) &stat->extension, &stat->n_uid, &stat->n_gid, &stat->n_muid); ret = req->result; + if ( ret ) + free_stat(&stat); put_free_req(dev, req); @@ -932,13 +934,13 @@ static int write_9pfs(struct file *file, const void *buf, size_t nbytes) if ( f9pfs->append ) { ret = p9_stat(f9pfs->dev, f9pfs->fid, &stat); - free_stat(&stat); if ( ret ) { errno = EIO; return -1; } file->offset = stat.length; + free_stat(&stat); } ret = p9_write(f9pfs->dev, f9pfs->fid, file->offset, buf, nbytes);
The early error exit in p9_stat() returns without zeroing the p9_stat buffer, resulting in free() being called with an uninitialized pointer. Fix that by calling free_stat() in p9_stat() in case of returning an error and potentially having allocated strings. Reported-by: Julien Grall <julien@xen.org> Fixes: 2d1dfccd3aa3 ("Mini-OS: add read and write support to 9pfsfront") Signed-off-by: Juergen Gross <jgross@suse.com> --- V2: - call free_stat() in p9_stat() in case of returning an error (Samuel Thibault) --- 9pfront.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)